Devices and methods for treatment of damaged tissue

ABSTRACT

Methods and devices for treatment of damaged tissue are disclosed, including treatment of wounds by employing non-electrically powered, reduced pressure therapy devices. Maintenance and control of the sub atmospheric pressure exerted may be provided by such devices while minimizing discomfort to the user. The devices may be configured to be worn inconspicuously underneath clothing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/372,661, filed on Feb. 17, 2009, which claims the benefit of priorityto U.S. Provisional Patent Application Ser. No. 61/028,835, entitled“Devices and Methods for Treatment of Damaged Tissue”, filed on Feb. 14,2008, which are hereby incorporated by reference herein in theirentirety.

BACKGROUND

The use of sub-atmospheric pressure to treat wounds can be traced backto ancient civilizations. For example, the ancient Chinese used“Cupping,” a technique that creates reduced pressure environment byflaming a glass chamber to draw out bad humors from the body. Modernresearch has revealed that applying reduced pressure to a damaged tissuemay have several beneficial effects: 1) a reduced pressure level maylead to retraction of the damaged tissue edges and thus may reduce thedefect size and may expedite healing by facilitating wound contraction;2) the reduced pressure may provide mechanical stimulation to thedamaged tissue which may release growth factors at the wound bed topromote healing; 3) the reduced pressure may create suction in thedamaged tissue cavity which may remove necrotic tissue from the damagedtissue cavity and may reduce bacterial load; 4) the application ofreduced pressure may increase blood flow to the damaged tissue and,which may expedite healing; and 5) reduced pressure may removegranulation inhibiting metalloproteinase enzymes, which may enhancetissue remodeling and healing.

In light of the many benefits of reduced pressure tissue therapy,reduced-pressure wound treatment systems and methods are desirable.

BRIEF SUMMARY

Methods and devices for treatment of damaged tissue are disclosed,including treatment of wounds by employing non-electrically poweredreduced pressure therapy devices. Maintenance and control of thesub-atmospheric pressure generated may be provided by such devices whileminimizing usage discomfort to the user. In some embodiments, thereduced pressure therapy device comprises a suction apparatus, a sealantlayer, a contact matrix and optional extension tubing. The suctionapparatus may be a non-electrically powered device, which may beconfigured to be silent and/or wearable. In some embodiments, thesuction apparatus may have a low-profile so that it may be worninconspicuously under clothing. The sealant layer may create asubstantially airtight enclosure over the damaged tissue to providefluid communication between the suction apparatus and the enclosurecontaining the damaged tissue. Fluid communication may be provided by adirect connection between the suction apparatus and the sealant layer,or may be provided through extension tubing connecting the suctionapparatus and the attachment port. In some embodiments, the sealantlayer may be flexible, but in other embodiments the sealant layer may besemi-rigid or rigid. In some examples, a semi-rigid or rigid sealantlayer may facilitate handling or application of the sealant layer to atreatment site while reducing or eliminating the risk that the sealantlayer may fold and adhere on itself. The extension tubing may be coupledto the sealant layer and/or suction apparatus using a connector orfitting. The connector may optionally comprise a releasable lockingmechanism to facilitate attachment and detachment of the extensiontubing, and/or to prevent accidental disconnection. For example, thereleasable locking mechanism may comprise a release button or otheractuator which serves as a locking mechanism which may be manipulatedduring attachment and/or detachment of the tubing. In other embodiments,the suction apparatus may be connected directly to the sealant layerattachment port, and may comprise a connector with the same or similarconnector as the extension tubing, to permit both direct attachment ofthe suction apparatus and remote attachment using the tubing.

In some embodiments the therapy device comprises a variable volumechamber configured to generate reduced pressure and to collect anyaspirated fluid or materials. The chamber may be actuated using constantforce springs which are coupled to a movable portion of the variablevolume chamber. By expanding or biasing the variable volume chamber toan increased volume, the volume of air enclosed by the variable volumechamber and the enclosure sealed by the containing the damaged tissuemay be expanded, thereby reducing the pressure of the air.

In some embodiments, the reduced pressure therapy device comprises anon-circular suction chamber design which may provide the therapy devicewith a low or reduced profile. In some examples, the low profile permitsplacement of the reduced pressure system on the body near the wound,with or without the use of extension tubing. This ergonomic chamberdesign coupled with the integrated system configuration may permitdiscrete wearing of the devices to enhance life quality. In oneparticular example, the suction apparatus comprises a variable volumechamber with an oval cross-sectional geometry that provides asubstantial exudate handling capacity while also providing a lowprofile. This permits improved mobility, discretion, flexibility, and/orcomfort during treatment. The low-profile geometry may also streamlinethe workflow of using the reduced pressure therapy system by locatingthe suction apparatus at or adjacent to the treatment site, rather thana remote site, and may also eliminate the use of extension tubing tomaintain fluid communication between a treatment site and a separatesuction apparatus.

The sealant layer may also comprise an attachment port to facilitateattachment and/or detachment of the suction apparatus or extensiontubing to the sealant layer. In some examples, the attachment port mayhave a variety of relative configurations and/or relative positions withrespect to the sealant layer and the suction apparatus. In someinstances, the attachment port may be articulated and/or flexible. Forexample, an attachment port may be configured with a swivel base, whichmay permit the attachment port to rotate. An articulated and/or flexibleattachment port may also reduce the transmission of torsion or otherforces that may be transmitted between the suction apparatus and thesealant layer. The attachment port may be integrally formed with sealantlayer at the point of manufacture, or may be provided separately andattached to the sealant layer at the point of use. The latterembodiments may permit clinician flexibility or customization of therelative location of the attachment port with respect to the sealantlayer. The attachment port configuration may also provide improvedpatient comfort as the attachment port design minimizes communication oftorsion forces to the wound bed, which may be caused by the suctionapparatus movements, while allowing quick integration. Furthermore,ability to bend and/or rotate allows independent placement of thesealant layer with respect to the attachment port orientation. Theflexibility of the attachment port may also reduce the risk of pressurepoint induced injury. The attachment port may allow for simple snap-inattachment of the vacuum source. The connection of the attachment portnozzle to the dressing interface may have a small footprint and/or a lowprofile to reduce the possibility of pressure point injury. In someembodiments, the swivel base of the attachment port may have a thinelastomeric base which is integrated into the sealant layer. The swivelbase is configured to allow maximal sealant layer moldability whilemaintaining integration with the more rigid system elements to form aseal around body surfaces. In some embodiments, a reduced pressuretherapy device with an attachment port may reduce or eliminate one ormore steps that are used to attach the reduced pressure source to thesealant layer and to create fluid communication between the wound andreduced pressure source. Unlike existing reduced pressure therapysystems, the attachment port may be configured to attach the vacuumsource without adhesives and/or without cutting the sealant layer.

In some embodiments, the reduced pressure therapy device may beconfigured with one or more actuators to facilitate activation of thesuction apparatus and/or release of the suction apparatus from the skinor tissue. For example, the suction apparatus may comprise an activationmechanism. In some embodiments, the suction apparatus contains a buttonor other actuator which initiates the application of reduced pressure atthe treatment site. The activation mechanism may be provide withindicia, such as the word “ACTIVATE” or a color green, or any other wordor coding with similar meaning, is provided thereon or nearby. Pressingthe said button may open a valve and allow fluid communication betweenthe enclosure formed adjacent to the wound bed and the suction chamber,or may unlock a sliding seal to permit movement. More specifically, theactivation may cause constant force springs to retract in order toexpand the combined volume of the space below the sliding seal andwithin the wound enclosure. The reduced pressure created therein mayexert a force on the sliding seal substantially equal to that of thesprings.

In some embodiments, the reduced pressure therapy device may furthercomprise an additional button or actuator which is configured to closethe valve and/or decouple the suction apparatus from the extensiontubing or sealant layer enclosing the wound. Pressing the additionalbutton may allow detachment of the suction apparatus from the attachmentport or the extension tubing and activate a one way valve which trapsthe exudates within the suction chamber or otherwise closes any pathwayout of the suction chamber.

In some embodiments, the therapy device may be primed or charged priorto applying the reduced pressure. In some configurations of the device,the charging and activating method may be performed in a singlecontinuous step. While in other configurations, the charging and theactivating method may be performed in distinctly separate steps. In oneexample, the sliding seal within the suction apparatus may be primed bybeing positioned at the distal end of the suction apparatus. Thepositioning of the sliding seal may be performed by any of a variety ofpriming mechanisms, such as a slider or push rod, for example. In someembodiments, the sliding seal may automatically begin to slide back togenerate a pressure differential in the reduced pressure chamber afterpriming. In other embodiments, the suction apparatus may comprise anactivating mechanism which is actuated separately from a primingmechanism to initiate the generation of the pressure differential. Insome configurations, the activating mechanism may directly block orrestrict movement of the sliding seal, while in other configurations,the activating mechanism may restrict or limit flow of fluid and/ormaterials into the chamber of the suction apparatus. In one example, therelease mechanism may comprise a separate button or lever that isconfigured to alter communication or flow through a valve coupled to thereduced pressure chamber. The valve may be a blade valve or rotatablevalve, for example. Pressing the activation button may lift a bladevalve or turn the lever of a rotatable valve to permit fluid flow intothe reduced pressure chamber.

In certain embodiments, the priming mechanism comprises a priming key ortool configured extend the force mechanism or displace the sliding sealinto its primed position. In some examples, the priming tool comprisesan elongate rigid member that is configured to be positioned in anopening in the body of the suction apparatus and may be used as a leveror push rod to prime the reduced pressure generation mechanism. In someembodiments, the priming tool can be used to mechanically press thesliding seal towards the distal end of the suction apparatus until alatch, embedded within the shaft of the priming tool, locks into place.In some embodiments the priming tool is integrated into the body of thesuction apparatus and may also serve as a cap to close the suctionapparatus. In some embodiments, the priming tool may be configured tohold and maintain the suction apparatus in a non-charged state. Forexample, the priming tool may be releasably locked to the body of thesuction apparatus to provide safe storage of noncharged suctionapparatus, with the locked priming tool preventing or limiting anon-charged spring mechanism from retracting during storage and/orhandling. In some instances, without the priming tool in place,retraction from storage and/or handling may occur, due to micro-leaksout of the suction chamber that may cause the springs to lose the energystored in them, for example. In other embodiments, the priming toolenables re-charging of the spring or other force mechanism that has beendepleted or otherwise lost some charge. For example, recharging may beperformed when accidental discharge or an undetected leak causes thesprings to lose the energy stored in them, or after emptying thecollection chamber.

Provided here is a tissue therapy device for treating a damaged tissue.In one embodiment, the device comprises a sealable wound covering and areduced pressure generating device. In some embodiments, the reducedpressure generating device may be wearable and configured tosubstantially maintain its external dimensions over a range ofcollection volumes. In addition, the reduced pressure generating devicemay have a non-circular cross-sectional shape. In some embodiments, thereduced pressure generating device may be non-electrically powered. Insuch an embodiment, the reduced pressure generating device may furthercomprise an elastic force member. For example, the force member may be aconstant force spring. In an embodiment where an elastic force member isused, the reduced pressure generating device may be adapted to bemechanically charged with potential energy. In some embodiments, thereduced pressure generating device may comprise a substantiallynon-cylindrical shape. In such an embodiment, the device may comprise atleast two suction chambers. In some instances, these multiple suctionchambers may operate independently. In some embodiments where thereduced pressure generating device comprises more than one suctionchamber, the device may further comprise at least one collection chamberthat is separate from the suction chambers.

Also provided herein is a device for treating a patient. In oneembodiment, the device comprises a sealable wound covering and anon-circular reduced pressure generating apparatus. In some embodiments,the sealable wound covering may further comprise a cover and anintegrated flexible attachment port, which may be configured to swivelaround a swivel axis perpendicular to the cover. In some instances, theattachment port may be configured to permit fluid communication throughthe sealable wound covering and with the reduced pressure generatingapparatus. In some embodiments, the non-circular reduced pressuregenerating apparatus may further comprise a suction chamber, which maybe configured to generate reduced pressure. In addition, the suctionchamber may be further configured to self-maintain a constant level ofreduced pressure across a volume range. In some embodiments, the reducedpressure generating apparatus may be configured to maintain a constantexternal configuration over a range of collection chamber volumes. Insome embodiments the volume of the suction chamber may be at least 50cc, but in other embodiments, the volume of the suction chamber may beat least 100 cc. In some further embodiments of the device describedherein, the reduced pressure generating apparatus may comprise anelastic force member. In such an embodiment, the reduced pressuregenerating apparatus may be configured to mechanically recharge theelastic force member. In some embodiments, the reduced pressuregenerating apparatus may be non-electronically powered.

Also provided herein is a device for treating a patient. In oneembodiment, the device comprises a sealable wound covering and anon-circular reduced pressure generating device. In some embodiments,the sealable wound covering may further comprise an integrated flexibleattachment port, which may be configured to provide fluid communicationthrough the wound covering and to seal around a wound to form a woundenclosure. In some embodiments, the attachment port may be configured toswivel substantially parallel to the sealable wound covering. In someembodiments, the non-circular reduced pressure generating device mayfurther comprise an elastic force member and a rigid member configuredto charge the elastic force member with potential energy. In such anembodiment, the elastic force member may be a constant force spring. Insome embodiments, the reduced pressure generating device may benon-electrically powered. In addition, the reduced pressure generatingdevice may be further configured to maintain a substantially constantpressure level irrespective of the orientation of the reduced pressuregenerating device with respect to gravity. In some further embodiments,the reduced pressure generating device may be configured to maintainfixed external dimensions irrespective of the suctioned or collectedvolume in the reduced pressure generating device.

Further provided herein is a system for treating a patient. In oneembodiment, the system provided herein comprises a sealable woundcovering and a non-electronically powered reduced pressure generatingassembly. In some embodiments, the sealable wound covering may furthercomprise a sealant layer and a flexible attachment port, which isconfigured with a lumen that passes through the sealant layer. In someembodiments, the system may further comprise at least one substantiallyconstant force member. In other embodiments, the system may furthercomprise at least two substantially constant force members. In someinstances, at least one force member is elastic. In some examples, atleast one elastic force member is a constant force spring. In anembodiment where a constant force member is used, the reduced pressuregenerating assembly may further comprise an elongate rigid member thatis configured to mechanically charge at least one constant force member.In a further embodiment of the reduced pressure generating assemblydescribed herein, the reduced pressure generating assembly comprises aseal assembly, which may be configured to slide in the suction chamberalong a movement axis. In such an embodiment, the reduced pressuregenerating assembly may be configured to maintain a fixed outerdimension along the movement axis independent of suction chambercontent. In addition, the reduced pressure generating assembly may beconfigured to maintain a fixed outer configuration independent ofsuction chamber content. In an embodiment where a seal assembly is used,the non-planar proximal perimeter of the seal assembly may be a curvednon-planar proximal perimeter. The reduced pressure generating assemblymay comprise at least one variable force member, and in some furtherexamples, at least one variable force member is configured to offset atleast some friction acting on the seal assembly. In further examples,the reduced pressure generating assembly comprises at least one ribbonspring, which may be a substantially constant force ribbon spring or avariable force ribbon spring.

In a further embodiment of a system for treating a patient where thesystem comprises a reduced pressure generating assembly, the reducedpressure generating assembly may comprises a first dimension, a seconddimension perpendicular to the first dimension, and a third dimensionperpendicular to the first and second dimensions. In some instances, thefirst dimension is the largest dimension of the reduced pressuregenerating assembly. In other instances, the second dimension is greaterthan the third dimension. In some embodiments the third dimension may beno greater than about 5 cm, but in other embodiments, the thirddimension may be no greater than about 4 cm, about 3 cm, about 2 cm, orabout 1 cm. In some embodiments where the reduced pressure generatingassembly comprises a suction chamber, the suction chamber may have avolume of about 500 cc or less. In other embodiments, the suctionchamber may have a volume of about 250 cc or less. In still otherembodiments, the chamber may have a volume of about 100 cc or less. Insome embodiments, the reduced pressure generating assembly may beconfigured to reduce the pressure under the sealable wound covering byat least about 75 mm Hg. In other embodiments, the reduced pressuregenerating assembly may be configured to reduce the pressure by at leastabout 100 mm Hg. In still other embodiments, the reduced pressuregenerating assembly may be configured to reduce the pressure by at leastabout 125 mm Hg.

In a further embodiment where the system for treating a patientcomprises an elongate rigid member, such elongate rigid member maycomprise a releasable locking mechanism. In some instances, thereleasable locking mechanism may comprise a latch and a release buttoncouple to the latch. In an embodiment where the system for treating apatient comprises a seal assembly, the seal assembly may comprise atleast one curved surface that is configured to push against at least oneconstant force member. In such an embodiment, the seal assembly mayfurther comprise at least one convex structure that is different fromthe above mentioned curved surface. In another embodiment, a system fortreating a patient may comprise a sealable wound covering and anon-electrically powered reduced pressure generating assembly, whereinthe reduced pressure generating assembly further comprises a valve. Insome instances, the valve is configured to control fluid communicationwith a suction chamber contained in the reduced pressure generatingassembly. In some embodiments, the valve may be coupled to a rotatableknob. In yet another embodiment, the system for treating a patient mayfurther comprise a connector tube that is configured to be coupled tothe sealable wound covering and to the reduced pressure generatingassembly.

Further provided herein is a system for treatment of a patient, wherethe system comprises a reduced pressure generating assembly and asealable wound covering, which further comprises a sealant layer and aflexible attachment port configured with a lumen that passes through thesealant layer. In some embodiments, the reduced pressure generatingassembly comprises a removable suction chamber with a longitudinal axisand a non-circular cross-sectional shape transverse to the longitudinalaxis and a volume of 150 cc or less. The reduced pressure generatingassembly may further comprise a piston assembly that is configured toslide in the suction chamber along the longitudinal axis. In someinstances, the piston assembly may have a non-circular cross-sectionalshape transverse to the longitudinal axis and a non-planar proximalperimeter. The reduced pressure generating assembly may further compriseat least two substantially constant force spring coils, which arecoupled to the piston assembly and configured to reduce pressure in thesuction chamber by at least about 50 mm Hg. In some embodiments, thereduced pressure generating assembly may further comprise a priming toolthat is configured to push the piston assembly. In some instances, thepriming tool may have a locking mechanism. In still other embodiments,the reduced pressure generating assembly may further comprise aconnector tube that is configured to releasably attach to the sealablewound covering and to releasably attach to the removable reducedpressure chamber.

In another embodiment, a method for treating a patient is provide, wherethe method comprises steps of (a) detaching a non-electrically poweredand non-circular reduced pressure generating device from a woundcovering, (b) charging the reduced pressure generating device withpotential energy without generating a reduced pressure, (c) attachingthe recharged reduced pressure generating device to the wound cover, and(d) activating the recharged reduced pressure generating device togenerate reduced pressure in an enclosure underneath the wound covering.

Further provided herein is a method for treating a patient, where themethod comprises steps of (a) sealing a wound cover to a body site, and(b) reducing the pressure level at the body site using a vacuumgenerating device that has an elongate length and a non-circularcross-sectional shape transverse to the elongate length. In someembodiments, the vacuum generating device may be configured to maintainsubstantially constant reduced pressure level at the wound site withoutchanging its external dimensions and independent of its orientation withrespect to the body site. In such an embodiment, the method may furthercomprise a step of sliding a non-circular seal along a movement axis ina non-circular reduced pressure chamber, wherein the seal and thesuction chamber have non-circular configurations transverse to themovement axis.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of various features and advantages of theembodiments described herein may be obtained by reference to thefollowing detailed description that sets forth illustrative examples andthe accompanying drawings of which:

FIG. 1 is a perspective view of one embodiment of the reduced pressuretherapy device comprising a suction apparatus, an extension tube and asealant layer.

FIG. 2 is a cut-away perspective view of one embodiment of a suctionapparatus of FIG. 1 in a primed configuration.

FIG. 3 is a cut-away perspective view of one embodiment of a suctionapparatus of FIG. 2 in a depleted configuration.

FIG. 4 is a perspective view of the embodiment of FIGS. 2 and 3 with apriming tool.

FIG. 5 is a perspective view of a sealant layer with an attachment port.

FIG. 6 is a cross-sectional perspective view of the sealant layer andthe attachment port of FIG. 5.

FIG. 7 is a perspective view of an extension tube connected to thesealant layer and attachment port of FIG. 5.

FIGS. 8A to 8C depict an exemplary method for connecting an extensiontube to a suction apparatus.

FIG. 9A to 9D are schematic illustrations of a reduced pressure therapydevice in various configurations; FIG. 9A depicts the device in a primedand locked configuration; FIG. 9B depicts the device in a primed andunlocked configuration; FIG. 9C depicts the device in an activatedconfiguration; FIG. 9D is a cross-sectional view of a portion of thepriming tool in FIG. 9C.

FIGS. 10A and 10B are schematic component views of another embodiment ofa reduced pressure therapy device, comprising a housing chamber and acollection chamber, respectively; FIGS. 10C and 10D, illustrate thereduced pressure therapy device of FIGS. 10A and 10B in non-primed andprimed configurations, respectively.

FIG. 11A is a perspective view of another embodiment of a reducedpressure therapy device comprising multiple chambers; FIG. 11B is an endview of the device in FIG. 11A; FIG. 11C-11E illustrate variousembodiments of a reduced pressure therapy device with multiple chamberswith respect to a sealant layer. FIG. 11F is a perspective view of theembodiment from FIG. 11A with a body strap.

FIG. 12 is a component view of another embodiment of a reduced pressuretherapy device, comprising a collection chamber and a housing.

FIG. 13A is a perspective view of another embodiment of a reducedpressure therapy device with a rotary activation interface. FIG. 13B isa cross-sectional superior view of the device in FIG. 13A.

FIG. 14A is a perspective view of another embodiment of a reducedpressure therapy device with an actuator having a rack and pinion; FIG.14B is a cross-sectional view of the device from FIG. 14A.

FIG. 15A is perspective view of another embodiment of a reduced pressuretherapy device; FIG. 15B the device of FIG. 15A held in a carrying casewith an attachment strap.

FIG. 16A is a perspective view of another embodiment of a reducedpressure therapy device; FIG. 16B is a superior view of the device ofFIG. 16A; FIGS. 16C and 16D are side and end elevational views, of thedevice from FIG. 16A; FIG. 16E is a perspective view of a device holder;FIG. 16F is a schematic perspective view of the device holder used withthe device; and FIG. 16G is a schematic illustration of embodiments forwearing or securing the device from FIG. 16A to a user's body.

FIGS. 17A and 17B are perspective views of exemplary embodiments of anattachment mechanism for the reduced pressure therapy device.

FIG. 18 is schematically illustrates another embodiment of an attachmentmechanism of a reduced pressure therapy device comprising an elastomerstrap.

FIG. 19A schematically illustrates another embodiment of a reducedpressure therapy device comprising a detachable and rotatable clip; FIG.19B is a posterior perspective view of the clip in FIG. 19A.

FIG. 20 is a perspective view of another embodiment of a reducedpressure therapy device comprising an integrated clip.

FIG. 21A is a perspective view of a reduced pressure therapy devicecomprising a viewing window and a vacuum indicator; FIGS. 21B and 21Care perspective views of other examples of reduced pressure therapydevices with various window configurations.

FIG. 22 is perspective view of one embodiment of a suction apparatus.

FIGS. 23A and 23B are posterior and anterior perspective component viewsof the embodiment from FIG. 22.

FIG. 24A depicts another embodiment of a reduced pressure therapy devicecomprising a clear collection chamber wherein the device is not primed;FIG. 24B depicts the device of FIG. 24A in a primed configuration; FIGS.24C and 24D or superior and side elevational views of the device inFIGS. 24A and 24B in an activated and partially expended state.

FIG. 25A is a superior elevational view of the suction chamber; FIG. 25Bis a cross-sectional view of the distal end of the suction chamber.

FIG. 26A is a component view of a fitting assembly; FIG. 26B is across-sectional view of the fitting of the fitting assembly from FIG.26A.

FIG. 27A is a schematic cut-away view of one embodiment of a connectingmechanism between a fitting and a suction chamber connector; FIGS. 27Band 27C are cross-sectional views of the connecting mechanism from FIG.27A.

FIGS. 28A and 28B are posterior and anterior component views of oneembodiment of a spring assembly, respectively.

FIGS. 29A and 29B are posterior and anterior perspective componentviews, respectively, of one embodiment of a piston assembly and springassembly. FIG. 29C is a front elevational view of the piston assembly.

FIG. 30 is a cross sectional view of one embodiment of a piston assemblycoupled to a spring assembly.

FIGS. 31A to 31C are schematic perspectives views depicting one exampleof a priming procedure using a priming tool.

DETAILED DESCRIPTION

While embodiments have been described and presented herein, thoseembodiments are provided by way of example only. Variations, changes andsubstitutions may be made without departing from the invention. Itshould be noted that various alternatives to the exemplary embodimentsdescribed herein may be employed in practicing the invention. For all ofthe embodiments described herein, the steps of the methods need not tobe performed sequentially.

Modern adaptations of techniques to provide reduced pressure to woundshave been developed recently. There are several commercially availablemodels of these types of reduced pressure dressing systems. Thesedevices may comprise an interface layer that is placed into the wound,an occlusive layer that creates a seal around the wound, connectiontubing that is in fluid communication with the interface layer and thewound, a separate exudates collection canister, and an electric pumpthat provides a source of vacuum. However, the electric pumps are bulkyand heavy thereby reducing patients' mobility especially duringprolonged treatment periods. These electrical pumps, in operation, canbe noisy and conspicuous. Further, the placement of the interface layer,the occlusive layer, and the connection tubing is labor intensive andtime consuming increasing patient dependence on health careprofessionals and further leading to higher health care costs. Thesesystems typically have non-disposable pumps and systemic components thatrequire significant maintenance and servicing and that carry the risk ofspreading contamination and infection. Although these systems can beused to treat smaller wounds, they are designed to treat large woundsand are not usually used to treat smaller wounds. Since current systemsdepend on electrical power for their operation, they further constrainpatient movement to areas having electricity or rely on limited batterypower where no electricity is available.

Described herein are devices configured to apply reduced air pressure(i.e., a vacuum) to a treatment site, such as a damaged tissue cavity orother type of wound. In some embodiments, the device may also be used toapply reduced pressure to otherwise undamaged tissue. In one embodiment,the tissue therapy device may comprise a sealant layer and a suctionapparatus. The sealant layer may be used to create a seal around an areaof tissue requiring therapy. The suction apparatus fluidly communicateswith the sealed enclosure formed by the sealant layer and reducespressure within the enclosure adjacent to the damaged tissue. In someembodiments, the suction apparatus may be non-electrically powered. Forexample, the suction apparatus may be configured to self-generatereduced pressure, i.e., without requiring a separate power or vacuumsource. A reduced pressure therapy device comprising a self-generatingreduced pressure mechanism may provide a patient with freedom andmobility without concerns of running out of battery power or havingaccess to an electrical outlet or vacuum generator. The sealant layerand the suction apparatus may be used to form a closed reduced pressuresystem to resist the backflow of gas into the system.

The reduced pressure may be self-generated by expanding the volume ofair initially located in the sealed enclosure and/or suction apparatusfrom a smaller volume of the enclosure to a larger volume shared betweenthe sealed enclosure and the suction apparatus. Upon expansion of theair within the sealed enclosure, the density of the air molecules isdecreased and the pressure within the sealed enclosure is reduced to asub-atmospheric level.

In one embodiment the tissue therapy device comprises a contact layermatrix that is placed into or over the wound bed or other tissue defect.In some embodiments, the contact layer matrix may be used to distributethe reduced pressure more evenly through the wound bed, and may alsoprovide a scaffold or contact surface which promotes healing. In anotherembodiment, the damaged tissue cavity, packed with the contact layermatrix, is then placed under a sealant layer to produce a sealedenclosure containing the contact layer and the wound bed. Fluidcommunication to the interior of enclosure is provided by an attachmentport of the sealant layer.

In some embodiments, the attachment port may comprise a collar with aninlet opening, a soft elastomeric body, and an outlet port. In someexamples, the collar may comprise a rigid or flexible material, and thecollar may be oriented at any of a variety of angles with respect to thesealant layer, including a perpendicular angle. The outlet port of theattachment port may also be flexible or rigid, and may be oriented atany of a variety of angles with respect to the sealant layer or collar.In some examples, the outlet port may be oriented generally parallel tothe plane of the sealant layer, or even below the parallel plane of thesealant layer, depending upon the height of the collar, but in otherexamples, the outlet port may be bent or angle above the plane of thesealant layer. The various components of the attachment port may or maynot be directly connected to one another, and the inlet and the outletmay have some degree of freedom of movement relative to one another.

In some embodiments of the device, the device may comprise a sealantlayer made of a hydrocolloid material or any other material known tothose skilled in the art. The hydrocolloid sealant layer may besemi-porous and breathable to absorb moisture from the wound whileprotecting the skin. In addition, the hydrocolloid sealant layer istypically thicker than other materials such as acrylic adhesives toallow for easier placement with less folding and wrinkling and to sealpotential fluid leak paths.

In one embodiment of the device disclosed herein, the attachment port isdirectly mounted to a distal portion of the suction apparatus. In otherembodiments the attachment port is connected to the suction apparatusvia an extension tube. In some embodiments, the extension tube may beadapted to mitigate entanglement. The suction apparatus and theextension tubing may have similar fittings and release buttons toprevent accidental disconnection. In embodiments in which extensiontubing is used, the distal end of the extension tubing is connected tothe distal end of the suction apparatus with similar fitting.

Some embodiments of the device disclosed herein comprise a pressuregauge integrated into the attachment port or another component. Themounting of the pressure gauge into the attachment port enables accuratemeasurement of pressure level within the enclosure adjacent to the woundand formed by the sealant layer. The pressure gauge described herein mayless susceptible to incorrect pressure readings that are typicallycaused by clots in the tubing connecting the reduced pressure source tothe wound.

In some embodiments of the reduced pressure system disclosed herein, thesuction apparatus reduces the air pressure within the enclosure adjacentto the damaged tissue by forcefully expanding the volume of air withinthe enclosure without changing the external dimensions of the reducedpressure generating unit. In other embodiments, the tissue therapydevice may self-regulate the pressure to a substantially constant level.

In one embodiment, the suction apparatus comprises a chamber, a slidingseal, a valve, and an activation system. The suction cartridge maycomprise a release button and an activation button in a distal portion.The activation button may be connected to a sliding blade valve whichprevents fluid communication from the enclosed area adjacent to thewound to the chamber when in the “off” position. When the activationbutton is depressed, the sliding blade valve may switch to an “on”position to permit fluid communication from the enclosure to thechamber. The activation button may be spring loaded to be biased to the“off” position but once it is depressed, a spring-loaded latch mayengage to remain in the “on” position. The release button may be adaptedand configured to allow detachment of any article (e.g., extensiontubing or sealant layer attachment port) from the suction apparatus andto terminate fluid communication between the suction chamber and theenclosed area. The release button may engage the interlock segment topull the latch away from the activation button. If the activation buttonis in the “on” position, it will revert back to the “off” position byvirtue of the spring loading.

In one embodiment of the reduced pressure system, the suction chambercomprises an ellipsoidal cylinder having a sliding seal concentricallydisposed therein. The chamber has a variable effective volume defined bythe distance between the distal end of the chamber, which is locatedadjacent to the opening connected to the sliding blade valve and acurrent position of the sliding seal. In the primed state, the seal isclosest to the distal end of the suction cartridge, and the effectivevolume of the chamber is zero or nearly zero. The sliding seal may beconnected to one or a series of springs which may be used to bias theseal towards an activated state where the effective volume of thechamber is the maximum. The springs may have any of a variety ofconfigurations, including ribbon springs. The ribbon spring may be asubstantially constant force spring or a variable force spring. In someexamples, a combination of spring types may be used. In still otherexamples, a single ribbon may be configured with a coil at each end andattached to a slidable seal at a middle region of the single ribbon. Inone embodiment of the device, the spring(s) may exert a force of lessthan 0.5 pounds. In other embodiments of the present invention theconstant force spring(s) may exert a force of less than 1 pound. In someembodiments of the reduced pressure system the constant force spring(s)may exert a force of less than 5 pounds. In other embodiments of thedevice disclosed herein the substantially constant force spring(s) mayexert a force of less than 20 pounds. In other examples, the force persquare inch exerted across the collection volume of the device may be inthe range of about 0.1 psi to about 50 psi, in some examples about 0.5to about 20 psi, and in other examples about 1.5 psi to about 5 psi.This pressure may be exerted by a single force member or may be theaggregate pressure from two or more force members. The force or pressuremay be selected based on the type, size, location, or another suitablecharacteristic of the wound being treated.

In some embodiments of the tissue therapy system the suction cartridgeis fabricated from a rigid polymer adapted to maintain the externalshape of the suction chamber shape under reduced pressure. The suctionchamber can be made of any suitable polymer such as, but not limited topolycarbonate, co-polyester, polyethylene, polypropylene, acrylic, ABS,glass, medical-grade polymers, or a combination thereof.

In other embodiments of the reduced pressure system, the sliding seal isfabricated from a material adapted to create an airtight separationbetween the portion of the suction apparatus below it and the remainderof the suction apparatus. The material may be elastomeric ornon-elastomeric. The sliding seal can be made of materials such as:silicone, fluorosilicone, nitrile, natural rubber, thermoplasticelastomer, thermoplastic urethane, butyl, polyolefin, polyurethane,styrene, polytetrafluoroethylene, any other suitable material, or acombination thereof.

In some embodiments of the tissue therapy system, the suction cartridgemay be coated using a friction mitigating lubricant to reduce movementof the sliding seal due to friction within the suction chamber and toreduce the likelihood of the seal sticking after being in a staticposition for prolonged periods. The lubricant coating material may bepolydimethysiloxane, perfluoropolyether, mineral spirits, syntheticoils, polyxylene, any other suitable lubrication polymer or material, orany combination thereof.

In one embodiment of the reduced pressure system disclosed herein thesuction apparatus springs are placed in a high potential energy extendedstate prior to activation. In other embodiments of the device, prior toactivation, the sliding blade valve is closed and the chamber iscompletely sealed. In such embodiments, the springs are prevented fromretracting because the extremely small volume of air in the chamberresists the expansion that would be caused by the constant forcesprings' retraction of the sliding seal. The device is ready to beactivated once the wound bed is sealed with the sealant layer, and thesealant layer is connected to the suction cartridge either directly orvia an extension tube.

When the tissue therapy system disclosed herein is activated, fluidcommunication is established between the suction chamber and the sealedwound enclosure. Since there is a finite amount of air within theenclosure (which is initially at atmospheric pressure), upon activation,the constant force springs will retract the sliding seal and expand theeffective volume of the suction chamber. As known by the ideal gas law,as a volume of air expands adiabatically, the pressure of the air willbe reduced, and subject the sealed wound enclosure to reduced pressure.

In some embodiments, the tissue therapy system may be used to maintain asubstantially constant level of reduced pressure despite the presence ofexudates and air leaked into the system. The sliding seal is amechanical system wherein the seal position is adapted and configured tobe in equilibrium based on the traction of the substantially constantforce springs, other traction elements in the system, and/or thepressure differential across the chamber seal. Other traction elementsin the system may include frictional forces (i.e. static and/or kineticfrictional forces). If the reduced pressure were to recover towardsatmospheric within the chamber, the pull of the springs would be greaterthan the pull due to the pressure differential. This, in turn, willforce the springs to retract and cause a simultaneous increase in thevolume of the chamber. This increase in volume will result in areduction of pressure away from atmospheric pressure within the chamber,until a new equilibrium is reached where the pressure differential andthe substantially constant spring force reach a new equilibrium. In someembodiments, the walls of the suction chamber are straight therebyensuring that the level of reduced pressure stays constant regardless ofthe actual position of the seal within the chamber.

In some embodiments, the suction apparatus may be configured to generatea reduced pressure which may be generally characterized by the absolutepressure level and/or by a pressure level reduction relative to theatmospheric pressure. In some embodiments, the device is configured togenerate a level of reduced pressure between about 0 and about 760 mmHg.In some embodiments, the generated amount of reduced pressure in theenclosure formed by the sealant layer and treatment site is more thanabout 10 mmHg, about 20 mmHg, about 50 mmHg, about 80 mmHg, about 100mmHg, about 150 mmHg, about 200 mmHg, about 500 mmHg, about 700 mmHg, oreven about 750 mmHg or more. The device may generate an absolute reducedpressure underneath the sealant layer where the reduced pressure isanywhere between about 0 and about 760 mmHg. In some embodiments, thegenerated level of reduced pressure in the enclosure formed by thesealant layer is less than about 700 mmHg, sometimes less than about 600mmHg, other times less than about 400 mmHg, or even less than about 250mmHg, about 125 mmHg, about 75 mmHg, about 50 mmHg, less than about 25mmHg, or less than about 10 mmHg. In some embodiments, the sealant layergenerally follows the perimeter of the area of tissue being treated. Thetissue therapy devices may have different collection chamber sizes whichallow for treatment of larger, more exudative wounds while maintainingthe smallest configuration possible for enhanced usage comfort. This maybe particularly advantageous for small wounds or treatment sites, as asmaller reduced pressure source can be partially or fully integratedinto the dressing or sealant layer. In some embodiments, the cavity ofthe suction apparatus is about 50 cc or less in volume, while in otherembodiments, the cavity may be about 100 cc in volume. In otherembodiments, the collection chamber is less than about 150 cc in volume.In some embodiments, the collection chamber is less than about 200 cc involume. In other embodiments, the collection chamber is smaller thanabout 300 cc in volume. In some embodiments, the collection chamber isless than about 500 cc in volume. In other embodiments, the collectionchamber is less than about 1000 cc in volume. In other embodiments, thecavity of the suction apparatus may be at least about 50 cc, about 100cc, about 150 cc, about 200 cc, about 300 cc, about 500 cc or about 1000cc or more.

In certain embodiments, the device comprises an elongated rigid memberthat fits into an opening the proximal end of the suction apparatus andserves as a lever that charges the constant force springs with potentialenergy by pressing the springs towards the device's distal end until thelatch, embedded within said lever, locks into place. In someembodiments, the elongated member is integrated into the suctionapparatus body and serves as a cap to the suction apparatus. In someembodiments, the elongated lever enables safe storage of the suctionapparatus as it prevents the springs from retracting due to micro-leaksthat may cause the springs to lose the energy stored in them. In otherembodiments, it enables recharging of the spring mechanism whenaccidental discharge occurs or an undetected leak is present while thedevice is in use.

In some embodiments, the suction apparatus comprises an elongated rigidmember adapted and configured to be inserted into a mating opening inthe proximal end of the suction generating unit. The elongated rigidmember contacts the rigid portion of the chamber seal and thus can beused to mechanically push the seal down the chamber against the constantforce springs thereby imparting potential energy into the constant forcesprings. This pushing motion is completed with the suction cartridgedisconnected from the extension tubing or attachment port, and with theactivation button and the sliding blade valve in the off position. Oncethe sliding seal reaches a point close to maximum spring extension, alatch tab on the elongate rigid member will engage a slot in the suctionapparatus body and prevent spring retraction. At this point, the slidingblade valve should be closed by depressing the release button therebysealing the chamber. The elongate member can then be removed by pressingthe latch tab leaving the suction apparatus ready for activation.

FIG. 1 illustrates one embodiment of a reduced pressure therapy device100, comprising a suction apparatus 101, an extension tube 102, and asealant layer 103. The sealant layer 103 may further comprise anintegrated attachment port 106 configured to connect the sealant layer103 to the extension tube 102 and/or directly to the suction apparatus101. In some embodiments, the connector of the extension tube 102 orsuction apparatus 101 may be configured to rotate about an axis ofattachment port 106. In some embodiments, the attachment port 106 may beconfigured to rotate around its base 110 and/or to bend toward and/oraway from the sealant layer 103. For example, the attachment port 106may be configured to freely rotate about 360 degrees or more, or toprovide a limited rotation range less than about 360 degrees, includingbut not limited to about 315 degrees, about 270 degrees, about 225degrees, about 180 degrees, about 135 degrees, about 90 degrees, orabout 45 degrees, for example. In other embodiments, the tubingconnector and/or the connector interface of the attachment may beconfigured to rotate with respect to the longitudinal lumen axis. Theattachment port 106 may have a fixed orientation that is generallyparallel to the plane of the sealant layer, but in other configurations,may be angled below the parallel plane or above the parallel plane. Instill other examples, the attachment port 106 may be configured to bendor pivot relative to the sealant layer 103. The range of bending orpivoting may be from about 0 degrees to about 45 degrees or about 90degrees, from about 0 degrees to 135 degrees or about 180 degrees, orfrom about −15 degrees or about −30 degrees to about 45 degrees, about90 degrees, about 135 degrees, about 180 degrees, 195 degrees or about210 degrees. In certain embodiments, the attachment port 106 may beconfigured to rotate and pivot.

The extension tube may be coupled to the attachment port by any of avariety of mechanisms. For example, the attachment port may comprise aresistance or interference fitting which may be inserted into the lumenof the extension tube. The resistance fitting may comprise one or moreflanges configured to resist decoupling of extension tube. In otherexamples, the extension tube may be inserted into the lumen or openingof the attachment port, and the attachment port may comprise a push-infitting, such as a John Guest fitting (Middlesex, UK). In otherembodiments, connectors on both components may be used, includingthreaded or mechanical interlocking fits. The connectors may beconfigured to facilitate both coupling and decoupling of the components.

In the example depicted in FIG. 1, one end of the extension tube 102comprises a port connector 105 configured to couple to a connectorinterface 111 of the attachment port, and the other end may comprise asuction apparatus connector 107 configured to couple to a connectorinterface 113 of the suction apparatus 101. In the depicted embodiment,the connector interface 111 of the attachment port 106 and the suctionapparatus connector 107 of the extension tube 102 may comprise male-typeconnectors, while the connector interface 113 of the suction apparatus101 and the port connector 105 of the extension tube 102 may comprisefemale-type connectors. The particular male-female configurationdescribed above is merely exemplary, and in other embodiments, themale/female configuration may be reversed, any other type ofcomplementary interface may be used, including interfaces which arenon-directional and permit the connector of the extension tube 102 inany direction. These or other complementary configurations may be usedto permit both the direct connection of the suction apparatus 101 andthe sealant layer 103, as well as the optional use of the extension tube102. In some embodiments, the extension tube(s) and/or the extensiontube connector(s) may be configured so that multiple extension tubes mayalso be joined together, either in a specific order or in any order. Theextension tube may also comprise one or more stress-relief or anti-kinkstructures, e.g. a helical winding or other tubular support, which mayresist pinching or other deformations of the tube. In FIG. 1, forexample, the port connector 105 and the suction apparatus connector 107of the extension tube 102 comprises a flared openings 115 and 117,respectively, which permit at least some deflection of the tube 102relative to the connectors 105 and 107 while distributing the bendingstress along the length of the flared opening 115 and 117 to resistpinching. In other embodiments, the stress relief structures of theconnectors comprise one or more bendable or deformable projections,which may or may not be flared.

One or more connectors of the extension tube may also comprise a lockingmechanism to facilitate decoupling and/or attachment of the extensiontube. In some examples, a locking mechanism may resist inadvertentdecoupling from the sealant layer and/or suction apparatus. In theexample depicted in FIG. 1, the port connector 105 of the extension tube102 comprises a locking mechanism with a connector release button 108configured to resist decoupling until the button 108 is pressed. Theconnector release button 108 may be coupled to a movable structure thatforms an interlocking or resistance fit with a complementary structureor surface on the attachment port 106. In some embodiments, theconnector release button 108 may be spring loaded or otherwise biased,and may or may not provide additional sealing and/or locking forcebetween the connector 105 and the attachment port 106. In othervariations, other locking interfaces, including sliders, levers orknobs, may be used. The attachment port 106 may comprise one or moregripping materials or textured gripping surfaces 109. The grippingsurface 109 on the exterior of the attachment port 106 may facilitatemanual connection and disconnection of the connectors on the extensiontube 102 or the suction apparatus 101. The grip surface 109 may compriseone or more flanges or ridges, for example, and/or a high tractionmaterial such as rubber or a block copolymer with polystyrene andpolybutadiene regions, e.g., KRATON® polymers by Kraton Polymers, LLC(Houston, Tex.). Gripping materials or structures may also be providedon the connectors 105 and 107 and/or the suction apparatus 101. In FIG.1, for example, the suction apparatus 101 comprises a nosepiece 104having a reduced width relative to the body 121 of the suction apparatus101. The nosepiece 104 may facilitate gripping of the suction apparatus101 when detaching or pulling it apart the extension tube 102 orattachment port 106.

In some embodiments, the suction apparatus may comprise a rigid polymerconfigured to generally maintain its shape under reduced pressure. Thesuction apparatus can be made of any suitable polymer such aspolycarbonate, co-polyester, polyethylene, polypropylene, acrylic, ABS,glass, or any other polymer known to those skilled in the art.

FIGS. 2 and 3 are detailed views of one embodiment of the suctionapparatus 101 in FIG. 1. The connector interface 113 may comprise aconnector 200 which may be coupled to the connector 107 at the proximalend of the extension tube 102, and/or the connector interface 111 of theattachment port 106 as depicted in FIG. 1. The suction apparatus 101 mayfurther comprise a sliding seal 207 located inside a suction chamber202. FIG. 2 depicts the sliding seal 207 in a distal position near thedistal end 208 of the suction chamber 202, and FIG. 3 depicts the seal207 in a proximal position near the proximal end 209 of the suctionchamber 202. The sliding seal 207 may be mounted on a seal mount 210 andis configured to traverse between the distal end 208 and proximal end209 of the chamber 202 while maintaining a substantial airtight seal.The suction chamber 202 may be also be characterized by the portions ofthe chamber 202 separated by the seal 207. For example, the suctionchamber 202 may comprise a collection chamber 216 located between thedistal end 208 of the chamber 202 and the seal 207, and a workingchamber 218 between the proximal end 209 of the suction chamber 202 andthe seal 207. The collection chamber 216 may be configured to generate areduced pressure and is in fluid communication with the connector 200 toprovide reduced pressure under the sealant layer 103. In the particularembodiment depicted in FIGS. 2 and 3, the collection of materialssuctioned from a wound and the generation of reduced pressure both occurin the collection chamber 216, but in other embodiments, the collectionchamber and reduced pressure generating chamber may be differentstructures.

The working chamber 218 of the suction apparatus 101 may contain one ormore force or bias members, and may also provide access to the seal 207to permit priming or charging of the force or bias members. A portion ofthe force or bias members may be attached or fixed to a portion ofworking chamber 218, while another portion is attached to the seal 207.In the particular embodiment depicted in FIG. 2, the force membercomprises two constant force springs 212 with proximal ends 215 mountedin the working chamber 218 using posts or pins 213, while their distalends 217 are attached a seal mount 210 that is coupled to the seal 207.In some embodiments, the seal 207 and the seal mount 210 may beintegrally formed. The sliding seal 207 may mounted on a seal mount 210by methods such as injection over-mold, adhesive bonding, or mechanicalbonding, or by a mechanical resistance or interlocking fit. In otherembodiments, the force members may be directly coupled to the seal 207.The functionality and structure of the seal 207 is described in greaterdetail below.

The volumes of the collection chamber 216 and the working chamber 218may vary, depending upon the position of the seal 207. In FIG. 2, wherethe seal 207 is in an extended position and in a primed configuration,the effective volume of the collection chamber 216 may be about zero orclose to zero. In FIG. 3, wherein the seal 207 is in a retractedposition, the effective volume of the collection chamber 216 may be ator near the volume of the suction chamber 202, notwithstanding thevolume taken up by the seal 207, seal mount 210 and/or the bias members.In other examples, the volume of the collection chamber may be generallybased upon the equilibration of the force generated by the bias membersand the counteracting force resulting from the reduced pressuregenerated in the collection chamber 216. The volume of the workingchamber 218 may be inversely related to the volume of the collectionchamber 216. In some instances, the maximum volume of the workingchamber 218 may be less than the volume of the suction chamber 202,which may result from volume displacement by the seal 207 or seal mount210, and/or by other structures located within the working chamber 218or structures which limit the movement range of the working chamber 218.

Access to the seal 207 may be achieved through the access opening 224located about the distal end 209 of the housing 220. As the sliding seal207 traverses from the extended position as depicted in FIG. 2 to theretracted position as depicted in FIG. 3, the interior volume of thecollection chamber 216 increases from about zero to about the maximumvolume provided in the fully retracted position, the suction apparatus101 comprises a collection chamber 216 with the maximum effectivecollecting volume. When the collection chamber 216 is in airtight fluidcommunication with a sealed wound enclosure and a good dressing seal isobtained within the wound enclosure, expansion of the volume of thecollection chamber 216 will reduce the pressure level in the sealedwound enclosure to a point where an equilibrium between the restoringforce applied on the sliding seal 207 by the constant force springs 212and the pressure differential across the sliding seal 207 is reached.

Some embodiments of the suction apparatus 101 may further comprise avalve 201 which may be configured to selectively permit fluidcommunication between the connector 200 to a collection chamber 216. Thevalve 201 may have any of a variety of configurations, including arotating cylinder valve or a blade valve, for example. The valve mayalso be a multi-directional valve, a bi-directional valve or a one-wayvalve. The configuration of the valve 201 may be controlled by anactivation button 203 or other type of actuator (e.g. a knob, switch,lever or slider). In some embodiments, the activation button 203 maycomprise a first configuration where the chamber valve 201 closes orblocks fluid communication between the collection chamber 216 and theconnector 200, and a second position where the valve 201 is open orallows passage of air and/or exudates to flow from the connector to thecollection chamber 216. In some further embodiments, some valves mayhave additional configurations to selectively permit infusion ofmaterials into the suction apparatus 101 and/or into the sealant layer,and/or configurations to selectively permit removal of air and/ormaterials from the collection chamber.

In further embodiments, a spring mechanism 204 may bias the valve 201 orits actuator to a closed or open position. For example, the springmechanism 204 may be configured to bias the valve 201 to a closedposition which blocks fluid communication between connector 200 and thecollection chamber 216. When the valve 201 is actuated to open the fluidcommunication, a latch mechanism 205 or other type of locking mechanismmay be used to engage the valve 201 and prevent the spring mechanism 204from closing the valve 201. The locking mechanism may also comprise arelease mechanism configured to permit selective disconnection orseparation of an extension tube or sealant layer. For example, theconnector 200 may be configured to prevent or resist disconnection ofany components connected to the suction apparatus 101 through theconnector 200 until a release button 206 or other actuator is depressedor manipulated. The release mechanism may comprise one or moredisplaceable or movable resistance or interlocking structures, forexample. In other embodiments, the lock and/or release mechanism may belocated on the extension tube or the attachment port of the sealantlayer.

In some embodiments, the release button 206 may comprise a mechanism tocontrol the valve 201. For example, the release button 206 may beconfigured to disengage the latch 205 from the valve 201, which permitsthe spring mechanism 204 to reposition the valve 201 to the closedposition blocks permit fluid communication between the connector 200 andthe collection chamber 216. In other embodiments, the release button 206may be configured to control a second valve in the fluid communicationpathway.

In some embodiments, the suction apparatus 101 may comprise a suctionchamber 202 with a non-circular cross-sectional shape, with respect to atransverse or perpendicular plane to the movement axis of the seal 207.The non-circular cross-sectional shape may include but is not limited toa generally rectangular or generally ellipsoidal shape, for example. Thesuction apparatus 101 may comprise a first transverse dimension that isgreater than a second transverse dimension, wherein each transversedimension is transverse to the movement axis of the sliding seal 407. Insome embodiments, the ratio of the first transverse dimension and thesecond transverse dimension is at least about 1.5, sometimes at leastabout 2, and other times at least about 3, or about 5 or more.

To prepare the suction apparatus 101 for generating a reduced pressurelevel in the sealed wound enclosure, the device is primed, i.e., thesliding seal 207 and the substantially constant force springs 212 may beplaced in a distal or extended position within suction chamber 202.Priming of suction apparatus 101 may be performed using a push mechanismor tool inserted through an opening 224 configured to provide access tothe seal 207 or seal mount 210. Examples of a push mechanism includingthe priming tool 400 depicted in FIG. 4, which is described in greaterdetail below. Referring back to FIG. 2, the sliding seal 207 is placedat an extended position, with the constant force springs 212 also in anextended state and charged with potential energy. In some embodiments,when the suction apparatus 101 is primed, the blade valve 201 is closedto seal the collection chamber 216. In these embodiments, retraction ofthe seal 207 by the constant force springs 212 is resisted or preventedbecause the small volume of air in the collection chamber 216 resiststhe expansion that would be caused by the retraction of the constantforce springs 212. The suction apparatus 101 may comprise a lockingmechanism to keep the sliding seal 207 in the primed position. In someembodiments, the priming mechanism or tool may also be used to keep thesliding seal 207 in position and resist retraction by the constant forcesprings 212

Once the wound bed is sealed with a sealant layer and the primed therapydevice is connected to the suction apparatus, the primed therapy devicemay be activated to generate reduced pressure in the wound bed. In someembodiments, a user of the therapy device described herein may activatethe therapy device by pressing down the activation button 203. In someexamples, prior to activation, the activation button 203 may be biasedto the “off” position. Pressing down or otherwise manipulating theactivation button causes the valve 201 to open fluid communicationbetween the collection chamber 216 and the sealed enclosure. Once theactivation button 203 is pressed down, a spring-loaded latch on theinterlock piece may engage to keep the activation button 203 in the “on”position.

When the reduce pressure therapy device is activated, fluidcommunication is established between the sealed wound enclosure and thecollection chamber 216. If a sufficient dressing seal is obtained withinthe sealed enclosure, there should be a finite amount of air and/orexudate within the sealed enclosure which is initially at atmosphericpressure. Upon activation of the suction apparatus 101, the chargedconstant force springs 212 that are will then retract the sliding seal207 and expand the volume of the collection chamber 216. Movement of thesliding seal 207 will stop at an equilibrium position where the tractionforce of constant force springs 212 is equal to the pressuredifferential across the sliding seal 207.

As the collection chamber is filled with exudates and/or air frompotential air leakage into the sealed wound enclosure or other locationin the system, the sliding seal 207 will retract towards the proximalend 209 of the suction chamber 202 until the constant force springs 212reach a retracted position, as depicted in FIG. 3. Further retractionmay be stopped either by a limit structure (if any) in the suctionchamber 202, or as a result of the decreasing counterbalancing force asthe reduced pressure collection chamber 216 returns to atmosphericpressure from increases in the joint volume shared by the woundenclosure and the collection chamber 216. The therapy device may then beremoved from the treatment site, or the suction apparatus 101 may bedisconnected from the sealant layer 103. As mentioned previously,disconnection may be achieved by pressing or actuating the releasebutton 206. Once the release button 206 is pressed down or actuated, theblade chamber valve 201 will be engaged in its “off” position which willterminate or block any fluid communication between the sealed woundenclosure and the collection chamber 216. Also, the spring-loaded latch205 on the interlock piece that forces or maintains the activationbutton 203 in the “on” position will be pulled away or otherwisemanipulated to permit the activation button 203 will revert to its “off”position.

As depicted in FIG. 4, some embodiments of the tissue therapy system maycomprise a priming tool or rod 400 which may be inserted into thesuction apparatus 101. The rod 400 may be pushed through an opening 224of the housing 220 to push the sliding seal towards the distal end 208of the suction chamber 202 and to charge the constant force springs withpotential energy. In some embodiments, the suction apparatus 101 may beconfigured so that the priming tool 400 contacts or engages the sealmount (210 in FIG. 2) at or adjacent to where the constant force springs212 are coupled to the seal mount 210. In other embodiments, the suctionapparatus 101 may be configured such that the priming tool 400 directlypushes against the springs 212, in addition to or in lieu of pushingagainst the seal mount 210. In some embodiments, once the sliding sealis moved to the primed configuration, a locking structure or latch 402located on the shaft 403 of the priming tool 400 may engage acomplementary structure (e.g. slot 219 in FIG. 3) of the housing 220.Thus, the priming tool 400 may be used to lock the seal into its primedconfiguration and resist the constant force springs from retracting andlosing its potential energy. The priming tool 400 may also comprise ahandle 412 to facilitate gripping and use of the tool 400.

In other examples, the priming mechanism may be used without removingthe priming tool from the device. In these embodiments, as the sealretracts, the priming tool will extend out of the accessing opening ofthe housing. In still other examples, a priming mechanism other than alinear push-based mechanism may be used, including but not limited toone or more rotatable knobs that may be used to unwind and extend thesubstantially constant force springs or other bias members to prime thedevice. In some other examples, where the force required to overcome thesprings and prime the device may be excessive, the priming tool may bethreaded and the priming tool opening may be configured with a screwdrive coupled to a handle that may provide a mechanical advantage to auser priming the device. In still other examples, embodiments comprisinga rotatable knob may comprise a slide-out handle, a swing out handle oran attachable handle to provide the user with greater torque whenwinding the knob.

Referring back to FIGS. 2 and 3, the access opening 224 may beconfigured to restrict or limit pivoting or angulation of the primingtool 400 during insertion. The housing 220 may also comprise guides 222that may further restrict or limit the motion of the priming tool 400during insertion. The priming tool 400 may also comprise guidestructures. FIG. 4, for example, depicts the priming tool 400 withridges or raised edges 410 which may facilitate tracking of the shaft403 along the constant force springs 212 as the springs 212 areextended. The distal end of the priming tool 400 and/or the seal mount210 may be configured with complementary interfaces to resist decouplingas force is being applied using the priming tool 400.

In some embodiments, the priming procedure described above may beperformed when the suction apparatus disconnected from any othercomponents, e.g., extension tubing, attachment port or sealant layer.After priming the suction apparatus, the suction apparatus is attachedto a sealant layer, directly or through extension tubing, the primingtool is removed, and the activation button on the suction apparatus ispressed to apply a reduced pressure within the sealed wound enclosurecreated by the sealant layer. In other embodiments, this priming processis completed with the activation button in the “off” position. Suchdesign may prevent elevated pressure from being applied onto the damagedtissue inadvertently. A one-way valve in communication with thecollection chamber may also be provided to expel air from the collectionchamber during the priming procedure. Referring still to FIGS. 3 and 4,in some embodiments, once the suction apparatus 101 is primed, a latchtab 404 or other actuator on the shaft 403 of the priming tool 400 canbe pressed or manipulated to disengage the latch 402 from theinterlocking slot 215, thereby allowing the priming tool 400 to bewithdrawn from the suction apparatus 101. In some embodiments, thepriming tool 400 may be left in the suction apparatus to ensure safestorage of the suction apparatus since it prevents the constant forcesprings from retracting due to micro-leaks. In some examples, thepriming procedure may be performed at the point-of-manufacture, while inother examples, the suction apparatus may be provided in an unprimedstate and primed at the point-of-use.

In some embodiments, the seal mount 210 may further comprise stabilizers211 which prevent or resist excessive angular displacement of thesliding seal 207 with respect to the primary axis of the suctionapparatus 101. The stabilizers 211 may comprise longitudinal extensionsor projections from the seal mount 210. The stabilizers 211 may or maynot have an orientation that is generally parallel to the longitudinalmovement axis of the seal 207. Also, a stabilizer 211 may be configuredto be in sliding contact with the wall of the suction chamber 202 alongits entire length, or may be configured to only partially contact thewall of the suction chamber 202. For example, a portion of thestabilizer may curve or angle away from wall of the suction chamber. Insome embodiments, the interior of the suction apparatus 101 furthercomprises a friction-reducing lubricant or a lubricous coating. In otherexamples, the seal and/or seal mount may have a variable thickness alongits perimeter or contact with the wall of the suction chamber. In someinstances, an increased thickness may increase the stability of the sealalong a dimension of the seal. In some examples, the portion of the sealand/or seal mount with the increased thickness may vary depending uponthe transverse dimension intersecting a) the portion of the perimeterand b) the central movement axis of the seal and/or seal mount. Otherexamples of seals and/or seal mounts with a variable thickness areprovided in greater detail below.

FIG. 5 depicts the sealant layer 103 of FIG. 1 without an attachedextension tube. The main body 500 of the sealant layer 103 may comprisea substantially flat, flexible material which is configured to form anairtight seal over a portion of tissue to be treated by adhering to theskin circumferentially to the damaged tissue section or wound. In someembodiments, the bottom surface of sealant layer 103 comprises apressure sensitive adhesive (PSA) layer 502, including but not limitedto any of a variety of silicone PSAs. The main body 500 of the sealantlayer 103 may comprise an average thickness between 0.001 and 0.5 inchesthick and may or may not be of sufficient thickness to resist wrinklingor inadvertent folding onto itself. As mentioned previously, theattachment port 106 may be configured to swivel about the axis normal tothe plane which approximates the surface of sealant layer 103. In someembodiments, the swivel range may be limited, but in other embodiments,the attachment port 106 is able to swivel 360 degrees or more. In someembodiments, attachment port 106 further comprises gripping surfaceswhich facilitate connection and disconnection of attachment port 106 toappropriate fittings.

FIG. 6 depicts a cross sectional view of the sealant layer 103. In thisembodiment, attachment port 106 further comprises a fenestration oropening 600 in the main body 500 of sealant layer 103 which is in fluidcommunication with a conduit 601 in the attachment port 106. In someembodiments, the sealant layer 103 further comprises a fixed swivelfitting base 602 which is adhered or attached to the main body 500 ofthe sealant layer 103. The attachment port 106 further comprises swivelfitting collar 603 which is mated to swivel fitting base 602 in anairtight manner and allows attachment port 106 to rotate about swivelfitting base 602. The attachment port 106 may further comprise aconnector 604 to facilitate airtight connection to other components,such as the extension tubing or the suction apparatus. In someembodiments, the connector 604 and/or the swivel fitting collar 603 ofthe attachment port 106 may be coupled to in flexible elastomeric body605. The conduit 601 passes through swivel fitting collar 603, a hollowsection of the elastomeric body 605 and the connector 604. In someembodiments, the swivel fitting collar 603 and connector 604 maycomprise a rigid material but the flexible elastomeric body 605 permitsrelative movement between the collar 603 and the connector 604. In someexamples, the flexible body 605 may be configured to permit some bendingwhile resisting pinching comprise one or more conduit support structuresto resist pinching of the flexible body that may result in blockage ofconduit 601.

In some embodiments, the device may be used for the treatment of lowerextremity wounds. The suction apparatus may be configured with a lowprofile with respect to its placement against the skin or body of apatient, e.g. the suction apparatus has a first outer dimension that issmaller than that is perpendicular to the surface that facilitates itsplacement on the leg or thigh underneath a normal pant leg, that lowprofile is achieved through non circular suction chamber design whichlowers the apparatus' profile while enabling the suction chamber tohandle large amounts of exudates. In some embodiments of the device itcomprises an attachment mechanism configured to attach the device to theuser's limb or torso, or to a belt or other article of clothing. In someembodiments of the device the attachment mechanism is a fabric leg stripwith adjustable self gripping fasteners. The fabric leg strip can beconstructed from cotton or foam or any other material known to thoseskilled in the art. In other embodiments of the device the attachmentmechanism is a flexible pocket adapted to contain the suction apparatusand attach to the body.

As mentioned previously, the reduced pressure therapy device may be usedwith an extension tube, and in some examples, the extension tube may becustom sized. The desired length of the extension tube 102 may bedetermined either by assessing the distance to the suction apparatusplacement location using the extension tube. As illustrated in FIG. 7,an extension tube 102 may be first attached to a sealant layer 103before cutting, but in other examples, the extension tube 102 may beattached or unattached to the sealant layer and/or suction apparatuswhen cut. Also, the sealant layer and suction apparatus may or may notbe applied to the treatment site or placement location when assessingthe extension tube length. Once the desired length of the extension tubeis determined, the extension tube 102 may be cut to remove a proximaltubing segment. As shown in FIGS. 8A to 8C, the extension tube 102 maybe connected to the suction apparatus 101 using a connector 802. A firstend 803 of the connector 802 may be configured for coupling or insertioninto a bare end of the extension tube, and in some examples, maycomprise one or more tapered structures 810, flanges 812 and/or barbs tofacilitate coupling and/or to resist decoupling. A second end 804 of theconnector 802 may be configured to connect to the complementaryconnector 805 of the suction apparatus 101. In other embodiments, aconnector is not required and the bare end or cut end of the extensiontube may be directly coupled to the suction apparatus 101. In stillother examples, both ends of the extension tube may be pre-attached withconnectors and a middle section of the extension tube may be cut out andthe two remaining sections can be joined together using a connectorwhere both ends are configured to attach to bare tubing.

Although the reduced pressure therapy device depicted in FIGS. 1 to 4comprises a suction apparatus 101 with separate “activation” and“release” actuators, in other embodiments, a single actuator with an“activation” and a “release” position may be provided. In still otherembodiments, no actuators may be provided. In some of the latterembodiments, the suction apparatus may begin to generate reducedpressure once the force from the priming tool is no longer applied. Inother examples, the suction apparatus may be configured with activationand/or release mechanisms that may open or close a valve from thecoupling or decoupling of the extension tube. For example, the suctionapparatus may comprise a slit valve which opens when the extension tubeor a connector is inserted into it.

FIGS. 9A to 9D illustrate another embodiment of a reduced pressuretherapy device 900 with a priming tool 902. FIGS. 9A and 9B depict thepriming tool 902 engaged in two positions: a primed position and anactivated position, respectively. To initially prime the reducedpressure therapy device 900, a user may insert and push the priming tool902 into an opening 905 in the body 906 of the device 900. As thepriming tool 900 contacts the seal mount of the sliding seal, thesliding seal is displaced towards the distal end 908 of the device 900,which extends the constant force springs attached to the seal mount andthus impart potential energy into the springs. In some examples, theopening 905 and/or the body 906 of the device 900 is configured tofacilitate the contact or engagement of the tool 902 to the seal or sealmount. For example, the opening 908 may be configured with acomplementary cross-sectional shape to the shaft 910 of the tool 902,and/or the body 906 of the device 900 may be configured with apassageway in communication with the opening 905, such thattranslational or angular displacement of the tool 902 is reduced. Insome examples, the tool may also be configured to track along the edgesand/or surfaces of the internal springs to facilitate contact orengagement to the seal or seal mount. For example, the shaft 910 of thetool 902 may be configured with one or more projecting edges 914. Theedges 914 may be configured to track along the edge(s) of the internalsprings. The distal end of the tool 902 may be configured with astructure complementary to a structure on the seal or seal mount whichmay reduce the risk of decoupling between the tool 902 as force isexerted by the user and/or by the springs.

In FIG. 9A, the priming tool 902 has pushed the sliding seal (not shown)from the proximal end 905 towards the distal end 908 of the device 900.The device 900 and the priming tool 902 may also be configured toreleasably lock the tool 902 and/or the sliding seal in its primedposition. In some examples, a device 900 with a locking mechanismpermits priming without requiring that the device 900 be attached to thesealant layer, or that the operator continue to exert force using thetool 902 until it is ready for activation. Any of a variety of lockingstructures or locking mechanisms may be provided, including but notlimited to interlocking fits or resistance fits between the device 900and the tool 902. For example, the handle 912 of the tool 902 may beconfigured with a locking flange (not shown) that may engage the opening905 of the device 900 to resist displacement of the tool 902 away or outof the body 906. Upon rotation, the flange may be disengaged to permitpassage of the flange out of the opening 905, along with the shaft 910of the tool 902. In the particular embodiment depicted in FIG. 9B, thepriming tool 902 may be configured so it may be rotated between a lockedand an unlocked configuration, but in other examples, a movable latch,locking pin or other interfering mechanism may be used instead of alocking flange. As shown in FIGS. 9B and 9C, once in the unlockedposition, the tool 902 may be removed to permit activation of the device900, or the force of the springs or bias mechanisms may push the tool902 out of the device 900 without requiring the user to pull the tool902.

In some embodiments, the reduced pressure therapy device may beconfigured to permit repriming of the device by re-actuating the tool.In other embodiments, the tool may be configured to permit limitedrepriming of the device, or no repriming of the device. As depicted inFIGS. 9C and 9D, for example, the tool 902 may be configured with one ormore projections 916 on the shaft 910. When the device 900 is activated,the internal springs may begin to bias the seal back to a proximalposition. In some instances, where a large volume of air exists underthe sealant layer, or the device 900 is improperly connected to thesealant layer, and/or the sealant layer is improperly applied to atreatment site, air may be immediately drawn into the device 900, suchthat the tool 902 quickly extends back out of the opening 905. Theprojections 916 may be configured to resist further retraction of theseal by the spring, while also remaining partially inserted into theopening 905. In some instances, this may be used by the user as anindicator to recheck the connections or sealant layer seal. Aftercorrecting or addressing the cause of an air leak, if any, the user maypush the tool 902 back into the body to re-prime the seal and then toregenerate the reduced pressure. In some examples, re-priming of thedevice using the tool may be repeated until the desired sealant layerseal is achieved. Once achieved, the tool 902 may be separated from thebody 906 of the device by exerting a pulling and/or twisting force todeform the projections 916 to allow removal of the tool 902. Theincreased force required to remove the tool 902 may reduce the risk ofinadvertent removal of the tool 902. Once removed, the projections 916may resist reinsertion of the tool 902 back into the device 900. In someexamples, limiting re-use of the device may reduce the risk ofcontamination that may be associated with aspiration of wound materialinto the device.

In some embodiments, the suction apparatus may comprise a separate orseparatable collection chamber which may be coupled or contained withina housing. The housing may be configured to interface with thecollection chamber and self-generate a reduced pressure level within thecollection chamber. In some embodiments, the housing further comprisesat least one force member that is configured to couple to the seal orseal mount located in the collection chamber. In some embodiments, apriming tool may be used to facilitate the coupling of the collectionchamber and the housing and/or to prime the seal. In some embodiments,the collection chamber of the suction apparatus may be separated fromthe housing, disposed and a new collection chamber may be coupled to thehousing. In other embodiments, the collection chamber may be separatedfrom the housing, emptied and/or cleaned, and then re-coupled with thehousing. During long-term use of the reduced pressure therapy device,the housing may also be replaced due to wear and tear of the housing orthe force member(s).

FIGS. 10A and 10B illustrate one another embodiment of a reducedpressure therapy device, comprising a housing 1002 and a collectionchamber 1000. The housing 1002 may comprising a housing opening 1004, ahousing cavity 1006, and at least one force member, e.g., a pair ofconstant force springs 1008, located in the housing cavity 1006, whichmay be configured to coupled to a seal 1010 located in a slidablearrangement in the collection cavity 1012 of the collection chamber1000. The springs 1008 may access the seal 1010 through a proximalopening 1014 of the chamber 1000. The seal 1008 may comprise a sealinterface 1026 that is configured to accept either the distal end(s) ofthe spring(s), and/or the distal end of a priming tool. The collectioncavity 1012 may comprise a flange or lip 1014 to resist separation ofthe seal 1010 from the cavity 1012. In some variations, a one-way valve1016 may be provided about the inlet 1018 of the collection cavity 1010.In some embodiments, the springs may be configured to attach to the sealas the collection chamber is inserted into the housing. For example, thedistal ends of the springs may be configured to form a threaded fit withthe seal by rotating the housing with respect to the collection chamber.In other embodiments, the distal ends of the spring may be coupled tothe seal using the priming tool, in addition to the use of the primingtool to prime the suction apparatus.

FIGS. 10C to 10D illustrate one example using the housing 1002 andcollection chamber 1000 of FIGS. 10A and 10B. A priming tool 1020 isinserted into the housing 1002 through an opening 1022 at the proximalend 1024 of the housing 1002. The tool 1020 may be used to push orextend the spring(s) 1008 or other bias member(s) located in the housing1002 into an extended configuration. The collection chamber 1000 and thehousing 1002 are then coupled together to engage the springs 1008 to theseal interface 1026 of seal 1010 while the springs 1008 are in theextended configuration. The engagement may be achieved by aninterlocking interfit or other type of complementary interfit. With thetool 1020 still in place, the collection chamber 1000 is then furtherpushed into the housing 1002, which pushes the seal 1010 into a distalposition in the collection cavity 1008, as illustrated in FIG. 10D. Thesprings 1008 and the seal 1010 are then primed and may be activated byremoval of the priming tool 1020.

Once the collection chamber 1000 is filled with exudates from thedamaged tissue and/or the potential energy in the springs 1008 isexhausted, the collection chamber 1000 may then be separated from thehousing 1002 by decoupling the springs 1008 from the seal 1010. In someexamples, the airtight separation provided by the seal 1010 protects thehousing 1002 from contamination and permits reuse of the housing 1002with a new collection chamber. In other examples, the housing 1002and/or the collection chamber 1000 may be reused, regardless of thesterility or contamination state.

In some embodiments the reduced pressure therapy device comprises aplurality of suction and/or collection chambers. In one embodiment, themultiple chambers may be disposed side by side, or end-to-end, or acombination thereof. In some embodiments, a suction chamber may alsoserve as a collection chamber. The chambers may have an elongateconfiguration and any of a variety of axial cross-sectional shape,including but not limited to circular shapes. The plurality of chambersmay be arranged such that the average perpendicular dimension (e.g.thickness) of the device with respect to the body surface of the patientwhere the device is worn is smaller than either of the other orthogonaldimensions of the device (e.g. width, length or diameter). The pluralityof chambers may be rigidly or flexibly coupled to each other. In someembodiments, the multiple chambers may be configured to form a generallyconcave surface, which may conform to a surface of the body site towhich the device will be attached. In some embodiments, the concavesurface substantially conforms to an arc with a radius that is betweenabout 1 cm and about 1000 cm, sometimes between about 5 cm and about 800cm, sometimes between 10 cm and about 500 cm, and sometimes betweenabout 50 cm and about 250 cm. The radius of such concave surface may beselected in part on the local topology of the body site to which thetissue therapy will be attached. A multi-chamber reduced pressuretherapy device may be used to provide a low-profile device while alsoproviding a large reduced pressure chamber volume and/or exudatehandling capacity.

FIGS. 11A and 11B illustrate one example of the reduced pressure therapydevice 1100 comprising multiple chambers 1102, 1104 and 1106. Althoughthe depicted example comprises three chambers 1102, 1104 and 1106, inother examples, a fewer or a greater number of chambers may be provided.The chambers may or may not have the same size or shape or feature set.For example, suction chamber 1104 may comprise a viewing window 1108 andan actuating knob 1110 which is configured to actuate reduced pressuregeneration in all three chambers 1102, 1104 and 1106. In some examples,two or more chambers, or all of the chambers may be configured to beindependently actuatable and/or configured identically. The number ofchambers may be in the range of about two chambers to about ten chambersor more, but other examples may be in the range of about three chambersto about six chambers. As illustrated in FIG. 11B, the suction chambers1102, 1104 and 1106 may be arranged to have a generally concaveconfiguration along at least one dimension or surface of the device1100, but in the same or a different embodiment, at least one dimensionor surface may have a generally planar configuration or a convexconfiguration. Alternatively, the device may have a variableconfiguration where at least the chambers 1102, 1104 and 1106 areflexibly connected or articulated. As depicted in FIG. 11B, theinterconnecting structures 1112 and 1114 of the device 1100 may be sizedand shaped to provide at least one generally smooth surface 1116, whichmay be the surface of the device 1100 configured to be placed againstthe body site of a patient. In other examples, the upper surface 1118 ofthe device 1100 may or may not also be smooth. The example depicted inFIGS. 11A and 11B may further comprise at least one attachment structureor mechanism, such as a strap or belt loop 1120 to facilitate wearing ofthe device with a strap or band 1121, for example, as shown in FIG. 11F.In other examples, the device may comprise a different attachmentstructure such as a hook, or one or more straps or belts may beintegrally formed with the device. The strap or belt may be similar tobelts used with a variety of clothing, but may also be configured forattaching the device to a patient's limb or the patient's abdomen ortorso. In the example shown in FIGS. 11A to 11F, the loop 1120 has awidth that is less than the corresponding dimension of the chambers1102, 1104 and 1106 and is configured to accept straps or belts ofsimilar width or less, but in other examples, the loop width may belarger than the corresponding chamber dimensions and/or may be openloops. In some further examples, the loops or other attachment mechanismmay be articulated or reconfigurable so that the relative orientation ofthe chambers 1102, 1104 and 1106 to the loops or attachment mechanismmay be changed, e.g. rotated. The strap or belt may comprise anattachment mechanism, such as a clip, buckle or hook and loopstructures, and may be elastic or inelastic. The width of strap or beltmay be in the range of about 1 cm to about 40 cm or more, in someexamples about 2 cm to about 30 cm, or in other examples about 5 cm toabout 20 cm. The loops may comprise a rigid or a flexible material, andmay have a fixed or an articulated attachment to the device.

In some embodiments that comprise multiple chambers, two or morechambers may function independently, or may be in fluid communicationwith each other in a parallel or serial arrangement. FIGS. 11C and 11Dillustrate two embodiments of a reduced pressure therapy system 1150 and1160 wherein each chamber 1102, 1104 and 1106 has it own inlet 1122,1124 and 1126, respectively. In FIG. 11C, each inlet 1122, 1124 and 1126of the system 1150 may be attached to a separate connector tube 1128,1130 and 1132, which are each connectable to a separate attachment ports1134, 1136 and 1138 of the sealant layer 1140. In some examples, asealant layer 1140 with multiple attachment ports or sites may be usefulfor treating separated or multi-cavity wounds, or treatment sites withmultiple tracts. In FIG. 11D, a branching extension tube 1142 maybe areduced pressure therapy device 1160 and a sealant layer 1144 where thedevice 1150 has a different number of inlets than the number ofattachment ports on the sealant layer. FIG. 11D depicts an example ofthe three inlets 1120, 1122 and 1124 of the device 1160 are connectedusing a branching extension tube 1142 to a single attachment port 1146of a sealant layer 1144. In other examples, only the reduced pressuretherapy device may have a fewer number of inlets as than the number ofattachment ports on the sealant layer. In still other examples, themultiple suction chambers need not be used simultaneously. Asillustrated in FIG. 11E, the suction chambers 1102, 1104 and 1106 of thesystem 1170 may be used sequentially, where the connector tube 1128 isdetached from an expended chamber and reattached to different chamber.Protective removable caps 1146 and 1148 may be used with the inlets 1120and 1124 of chambers 1102 and 1106 not currently connected to aconnector tube. In other embodiments, the device may comprise amulti-port valve which may be used to change the communication betweenan inlet and a suction chamber, so that separate inlets for each chamberare not required.

As mentioned previously, a reduced pressure therapy device comprising aplurality of chambers may have chambers with different features and/orfunctions, including devices with both suction chambers and collectionchambers. As depicted in FIG. 12, in some embodiments, the reducedpressure therapy device 1200 may comprise a housing 1202 and acollection chamber 1204. The housing 1202 may comprise one or moresuction chambers 1206 and 1208. In this particular example, the housing1200 comprises two suction chambers 1206 and 1208 which are located toeach side of the housing 1202 and with a collection cavity 1210 betweenthe suction chamber 1204 and 1206 configured to receive the collectionchamber 1204. The collection cavity 1210 may also be configured to alignany openings 1212 and 1214 or channels of the collection chamber 1202with corresponding openings 1216 and 1218 or channels of the suctionchambers 1204 and 1206. In this particular embodiment, the housing 1202comprises a housing inlet 1220 which may be in fluid communication witha collection inlet 1222 of the collection chamber 1202 when thecollection chamber 1202 is inserted into the housing 1200. Each suctionchamber 1206 and 1208 may comprise one or more force members, e.g.constant force springs 1224 and 1226 coupled to a movable seal (notshown). In use, the collection chamber 1204 is in fluid communicationwith the sealed wound enclosure and may be replaced or emptied when itis filled up by exudates from the damaged tissue or when the potentialenergy of the force members is depleted. The device 1200 may alsocomprise at least one smooth concave surface 1228 that is designed toconform to the contours of the body site to which the device is secured.The opposing surface 1230 of the device 1200 may or may not have aconvex surface, as depicted in FIG. 12. The device 1200 may alsocomprise a cap or cover 1232, which may be useful to protect dirt entryinto the housing 1200, and/or to secure the collection cavity 1202 tothe housing 1200. The cover 1222 and housing 1202 may or may not beconfigured to form an airtight seal. In other examples, the collectionchamber 1204 may be configured with an integrated cap or cover. Thecollection chamber 1204 may be configured to be secured to the housing1200 by a resistance interfit or a mechanical interlock, for example. Inuse, because the collection chamber 1202 does not contain the primingand activating mechanism, e.g., constant force springs and a primingtool, the device 1200 may be easier to replace and/or clean. Once thecollection chamber 1202 is filled up with exudates, the user can replacethe filled collection chamber 1220 by inserting a new chamber into thehousing chamber 1210 and repeating the priming and activating steps asdescribed elsewhere. In use, the device 1200 may be oriented so that thehousing inlet 1220 is located inferiorly relative to the rest of thedevice 1200. In this orientation, any exudate aspirated into thecollection chamber is less likely to reach the openings 1216 and 1218 ofthe collection chamber 1204 and fill the suction chambers 1206 and 1208with exudate. In some examples, filter structures may be provided in thesuction chambers 1206 and 1208 and/or the collection chamber 1204 toresist or block entry of non-gaseous material into the suction chambers1206 and 1208.

In some embodiments, the reduce pressure therapy device 1300 maycomprise a multi-position actuator, such as a slider or rotary controlknob 1302, as illustrated in FIGS. 13A and 13B. In some embodiments, therotary knob 1302 may be coupled to a valve 1304 which may be configuredwith at least two positions: an “open” position and a “closed” position.The device 1300 may be primed by changing the knob 1302 to the “open”position which permits fluid communication through the control valve1304 to expel any air out of the collection chamber 1306 during priming.When the knob 1302 is placed at a “closed” position, the fluidcommunication is blocked to resist inflow of air or other materials intothe collection chamber 1306. The device 1300 may then be attached to asealant layer and the activated by turning the knob 1302 to permittransmission of the reduced pressure in the collection chamber 1306. Insome examples, a low-profile knob may reduce the risk or avoid aninadvertent activation and/or release of the device compared to devicescomprising push buttons. As mentioned elsewhere, the knob and itsassociated mechanism may also be configured with additional positions orstates. For example, the knob may also have a separate priming positionwhich permits the air or gas in the chamber 1304 of the device 1300 tobe expelled during the priming procedure without causing pressurebuildup. In other examples, however, a continuous one-way valve may beprovided to vent any pressure buildup in the collection chamber. In someother examples, the knob and/or the valve mechanism may be configured tobe single-use, which may reduce the risk of re-using a non-steriledevice. In still other examples, the device may be configured to beprimed when the device chamber is not attached to the knob housing 1308and therefore does not require any passageway to expel the gas. Besideschanging the fluid communication, the knob mechanism may also beconfigured to provide release position which permits detachment of thedevice chamber 1304 and the knob housing 1306.

As depicted in FIGS. 14A and 14B, in some embodiments, the therapydevice 1400 may comprises a rack and pinion mechanism 1402 configured tocharge the constant force springs 1404 and to position the sliding seal1406. In this depicted embodiment, the device 1400 comprises arecharging handle 1408, providing two sets of rails 1410 with rack teeth1412. Two sets of pinions 1414 are mounted near the proximal end 1416 ofthe suction apparatus body 1418. The number of rails and pinions in anyparticular example may vary, depending upon the number of springs. Thepinions 1414 are coupled to the constant force springs 1404 which areconnected to a sliding seal 1408. The circular motion of the pinions1414 will drive the motion of the springs 1404 to charge the springs1404 with potential energy.

The rack and pinion charging mechanism 1402 may be provided in additionto or in lieu of a priming tool charging mechanism. In some examples,when an inadequate seal or connection is made and air enters the closedsystem, the recharging handle 1410 may be pulled away from the proximalend 1416 of the suction apparatus 1418 and then pushed back towards theproximal end 1416 to recharge the springs 1404. In some examples, therails and the pinions may be configured to engage in only one directionand not the other, to permit repeat manipulation of the chargingmechanism 1402 to increase the magnitude of charging. A deviceconfigured with one-way movement of the rack and pinion mechanism mayalso permit retraction of the seal and springs without requiring thatthe rack and pinion handle correspondingly retract. Once the device 1400is re-charged and the dressing seal and/or connections are rechecked,the device 1400 may be reactivated to generate a reduced pressure.

FIGS. 15A and 15B depict another embodiment of a reduced pressuretherapy device 1500, comprising a slidable lever 1502 that is providedon the body 1504. The slidable lever 1502 is coupled to the sliding seal1506 using a flexible element 1508 that is configured with sufficientcolumn strength to push the seal 1506 when the flexible element 1508 ispushed using the lever 1502, yet sufficiently flexible bend along thepassageway containing the element 1508. The flexible element 1508permits the lever 1502 to move in a different direction than the seal1506, which may or may not permit more compact device designs. Inalternate embodiments, the flexible element may be configured to pull,rather than push, the seal to a primed position using a slidable lever.In some examples, both a priming tool mechanism and the slidable levermechanism may be provided for priming the device. As the seal 1506 movesin response to suction of air or exudates, the flexible element 1508will in turn cause movement of the lever 1502. In some examples, theposition of the lever 1502 may be used as an indicator of the remainingpotential energy in the device 1500, and in some instances, indicia onthe body 1404 near the path of the lever 1502 may be provided toindicate the remaining energy or fill capacity.

In other embodiments, the reduced pressure tissue therapy device may beconfigured as a portable device that may be carried by the patient orcarried the patient's ambulation assistance device (e.g., wheelchair orwalker). In other embodiments, the tissue therapy device is designedsuch that it may be secured to the patient (e.g. limb or torso). Thetissue therapy device may be attached to the patient by any suitablemeans for securing the device to the patient known to those skilled inthe art. In some embodiments, the device may be secured through the useof adhesive tape. In other embodiments, the device may be secured to thepatient through the use of a strap, a hook-and-loop fasteners such asVELCRO®, an elastic band, a cuff, an adhesive bandage, or any othersuitable mechanisms for securing the device. In other embodiments, thedevice comprises a detachable clip. In yet other embodiments, the devicefurther comprises a holster or other type of pocket structure to holdthe suction apparatus.

As illustrated in FIG. 15B, the reduced pressure therapy device 1500 maybe kept in a pouch 1510 or other holder that can be further attached toa belt or a wrap 1512, for example. The pouch 1510 may comprise anopening 1514 through which an extension tube 1516 of the device 1500 canextend. The pouch 1510 may also comprise a viewing opening or window1524 which have a pouch location that corresponds to a viewing window ofthe device 1500, for example. As may be seen in FIGS. 15A and 15B, thesuction inlet 1518 need not be coaxial with the movement axis of theseal 1506. Furthermore, the control valve 1520 of the device 1500 mayalso comprise a non-linear valve conduit 1522 that need not pass throughthe rotation axis (if any) of the valve 1520.

In some embodiments, the tissue therapy device may be held or encased insoft or resilient materials, e.g., a dense foam. In some instances, useof foams or other soft or resilient materials may increase comfortduring use, and may reduce the risk of injury to the device or the userwhen the device is accidentally bumped, or from pressure points that mayoccur with long-term use. FIGS. 16A to 16E illustrate one example ofsuch a device 1600. In some examples, the soft covering 1602 isintegrally formed with the device 1600, while in other embodiments, thedevice 1600 may be removable and re-encased in the soft casing 1602. Insome examples, the device 1600 and the soft casing 1602 may havedifferent outer shapes or colors, which may permit changing ofornamentation to mask the nature of the device 1600, which may improvepatient confidence using the device in public and/or patient compliancewith the device 1600. In another example, an oval casing may beconfigured to engage a box-like device to eliminate any corners.Moreover, the greater surface area of such casing may reduce the risk ofcausing focal pressure points or regions as a result of securing thetissue therapy device directly to a user's body. To reduce potentialbulkiness, the casing 1602 need not fully encase the device 1600 and mayhave one or more openings 1604. Openings 1606 may also be provided toaccess to chamber windows or actuators of the device 1600, or to removea collection chamber from the device 1600. The device 1600 may alsocomprise an internal frame 1608 to support components of the device 1600such as the valve or spring posts (not shown) for example.

In one further embodiment, the encased therapy device 1600 may beconfigured to attach to a strap 1620 which may permit the encased device1600 to snap into a cavity 1622 of the strap. Alternatively, zippers orother fastener mechanisms may be used to secure the device 1600 into thecavity 1622. In some examples, a soft casing 1602 is not used orprovided, and the materials about the cavity 1622, if not at least aportion or all of the strap, comprises soft materials. The strap maycomprise a closed loop of elastic material, or may comprise an open loopwith a buckle, clasp or other fastening mechanism that may be used toclose the loop. As depicted in FIG. 16E, the strap 1620 may be worn in avariety of ways to secure the device to the user, including the waist oracross the torso. In still other embodiments, the device is not securedagainst the user and may be carried as a loose shoulder strap.

FIGS. 17A and 17B illustrate another example of an attaching mechanismfor a suction apparatus 1700, comprising at least one elastomeric band1702 and 1704 attached to the body 1706 of the suction apparatus 1700.Bands of various sizes, i.e., length, width, thicknesses,cross-sectional shapes and a variety of materials can be included in thetherapy device kit to suit different needs. For example, larger bandsmay be provided for attachment around the limbs or torso. These largerbands may be removed by the user and replaced with shorter bandsprovided for attachment to a belt, strap or sash. The ends 1708, 1710,1712 and 1714 of the bands 1702 and 1704 may be configured to bereleasably attachable to the body 1706 of the device 1700, which maypermit crossing or interlocking of the bands 1702 and 1704, as shown inFIG. 17B. In some instances, as illustrated in FIG. 17B, the twoelastomer bands 1702 and 1704 may be crossed over when coupled to thebody 1704 of the device 1700 for use with a belt or wrap 1716 that canbe worn by the user. In FIGS. 17A and 17B, while each end 1708, 1710,1712 and 1714 of their respective bands 1702 and 1704 are be coupled toattachment sites 1722 and 1728 on the same end cap structure 1718 and1720 of the body 1704, in other examples, at least one band may haveends coupled to different end cap structures. The attachment sites 1722,1724, 1726 and 1728 are located on the sides of the end cap structures1718 and 1720, but in other embodiments may be located on the endsurfaces or the top or bottom surfaces of the end cap structures or thecollection chamber 1730. In some instances, it may be beneficial to useat least one band 1702 and 1704 to keep attach the end cap structures1718 and 1720 together when the when the collecting chamber 1730 isremoved from the device 1700.

Although the bands 1702 and 1704 in the embodiment illustrated in FIGS.17A and 17B have a generally elongate configuration, otherconfigurations are also contemplated, including I-shaped, H-shaped orX-shaped bands. In some examples, a single band structure may be coupledto more than two or even all of the attachment sites. In FIG. 18A, forexample, the device 1800 comprises a H-shaped strap 1802. In someexamples, a H-shaped strap 1802 may result in less interference with thesurface 1804 of the device 1800, which may facilitate the application ofadhesive labels, writing or other indicia onto the device 1800. In someexamples, this strap configuration may permit multiple ways for a beltor a wrap to pass through the strap and may provide flexibility to theuser on how to wear or secure the device. Referring back to FIG. 17, thebody 1704 of device 1700 may have fewer or a greater number ofattachment sites 1722, 1724, 1726 and 1728 than four, and not everyattachment site needs to be used. In other embodiments, multipleattachment structures or openings may be provided on the band so thatthe cross-sectional area between the band and the body of the device canbe adjusted. In still other embodiments, the attachment sites on thebody of the device may be configured to slide, rotate and/or pivot. Thestructure of bands may be uniform or non-uniform along any dimension ofthe bands, e.g. a band may have a greater width in a central segment ofthe band compared to the end segments.

In yet another embodiment of a reduced pressure therapy device 1900 inFIG. 19A, the device 1900 comprises an attachment site with a mountingpost or stud 1902 that may be coupled to slotted opening 1904 of the aclip 1906, as shown in FIG. 19B. Referring back to FIG. 19A, in certainembodiments, the clip 1906 and the post 1902 are configured to permitrotation of the device 1900 with respect to the clip 1906. The clipattachment site may be located anywhere on the body of the device. Inother examples, the clip mechanism may be releasably attached to thedevice 1900 using any of a variety of other interfaces, including butnot limited to where the attachment site on the body of the devicecomprises an opening, recess or groove and the clip comprises acomplementary post or other structure configured to couple to theopening, recess or groove. The clip may have any of a variety of lengthsor widths, and in some examples, multiple clips with differentconfigurations may be in a kit containing the device. Although the clip1904 in FIG. 19A is articulated with a spring biased pivot mechanism1908, in some the clip may have a generally fixed configuration andcomprise a rigid or semi-rigid material. Also, in other embodiments, theclip structure may be integrally formed with the body of the device. InFIG. 20, for example, the reduced pressure therapy device 1920 comprisesan integrally formed, unarticulated clip 1922 that is attached to one ofthe end caps 1924 of the device 1920. The distal end 1926 of the clip1922 may have an increased thickness, which may resist inadvertentseparation of the clip 1922 from the belt or strap to which it may beclipped.

Referring back to FIG. 17A, in some examples, the device 1700 maycomprise a priming tool 1740 with a locking actuator 1742. The actuator1742 may be configured deform or displace a locking structure of thetool 1740 or to otherwise unlock the tool 1740 to permit its movement.The unlocked movement may include axial and/or rotational displacement.The locking actuator 1742 may be configured to resist, for example,inadvertent activation of the device 1700 or withdrawal of the primingtool 1740.

In some embodiments, the suction apparatus may comprise a window orviewing region which permits visual assessment of the pressure leveland/or the exudates without removal or opening of the device. FIG. 21Aillustrates one example of a non-circular suction device 2000 comprisinga longitudinally oriented window 2002 located on a surface 2004 of thedevice 2000. The non-circular seal may be viewable through the window2002 and the seal may comprise seal indicia which may be viewed withrespect to body indicia or window indicia 2010 to assess the position ofthe seal and/or the remaining amount of potential energy remaining inthe device 2000. An exudate volume scale or set of indicia may also beprovided about the window. In some examples, by tilting the device andutilizing gravity, the amount of exudate contained in the device 2000may be assessed using the volume scale. In some further examples, morethan one window region may be provided. Referring still to the device2000 in FIG. 21A, a proximal window 2012 may be provided along adifferent circumferential region from the first window 2002 with respectto the longitudinal movement axis of the seal 2006. When the seal 2006is in a proximal region, indicia or a different surface of the seal 2006not visible when the seal 2006 is distal to the proximal region may bevisible at the proximal window 2012, and may be used to indicate thatthe potential energy in the device 2000 has been depleted, that thedevice has not been charged, and/or that the device has failed. In otherexamples, a distal window (not shown) may also be provided to indicatethat the device has been primed. The region of the seal configured to bevisible at the distal window may or may not be circumferentially alignedwith the proximal window of the device (if any). In some examples, theproximal window and/or the distal window has a dimension as measuredalong the movement axis of the seal that is less than the dimension ofthe seal along the movement axis if the seal. In some specific examples,the dimension of the proximal and distal window as measured along themovement axis is 50% or less than the dimension of the seal along themovement axis if the seal.

Although the window(s) of the reduced pressure therapy device may becircular, ovoid, square, rectangular or otherwise polygonal (with sharpangles or rounded angles), and each window may be limited to one surfaceof the device, in other examples, the windows may have any of a varietyof shapes and may span two or more surfaces of the device. In FIG. 21B,for example, the device 2020 comprises a window 2022 with a longitudinalregion 2024 that is contiguous with a transverse proximal region 2026and a transverse distal region 2028. As illustrated in FIG. 21B, theproximal and distal regions 2026 and 2028 may be configured to span asuperior surface 2030 of the device 2020 as well as the side surfaces2032 and 2034. The longitudinally configured portions of the windowsneed not have a uniform width, and the proximal and distal regions ofthe window (if any) need not have the same configuration. FIG. 21C, forexample, depicts a device 2040 comprising a window 2042 with alongitudinal region 2044 that tapers distally and also comprises aproximal region 2046 but not a distal region.

In some embodiments, a method of applying reduced pressure therapy to anarea of damaged tissue is provided, comprising: affixing a sealant layeraround an area of tissue to be treated; creating a sealed enclosurearound the area of the tissue with the sealant layer; priming a suctionapparatus by positioning a reciprocating member contained in the suctionapparatus to an extended position where the effective collecting volumeof the suction apparatus is about zero; creating a fluid communicationbetween the sealed enclosure and the suction apparatus; and activatingthe suction apparatus by drawing back the reciprocating member to aretracted position thereby forcefully expanding the volume of the airoriginally located within the sealed wound enclosure and generating areduced pressure level within the sealed enclosure.

Another embodiment of a suction apparatus 2200 is illustrated in FIGS.22, 23A and 23B. Suction apparatus 2200 comprises a suction chamber 2210having a distal end 2212 and a proximal end 2214, a front cap 2220 and arear cap 2230. The front cap 2220 and the rear cap 2230 may beconfigured to be detachably secured to the distal end 2212 and theproximal end 2214 of the suction chamber 2210, respectively. Theproximal end 2212 and/or the distal end 2214 of the suction chamber 2210may also comprise notches 2360 and 2370, respectively, which may beconfigured to facilitate coupling to the rear cap 2230 and/or front cap2220 of the device 2200, respectively. Notches 2372 or apertures mayalso be provided for attaching the spring assembly 2270 to the suctionchamber 2210. A fitting housing 2240 may be coupled to the front cap2220, enclosing a fitting 2242 that may be configured to connect thesuction chamber 2210 with another component of the therapy system (e.g.,an extension tube or an attachment port on a sealant layer). The suctionchamber may be fabricated from a rigid polymer adapted to maintain theexternal shape of the suction chamber shape under reduced pressure. Insome embodiments, the entire body of the suction chamber may betransparent, thereby permitting visual inspection the quantity andquality of wound exudates contained therein. In other embodiments, thesuction chamber may comprise a non-transparent body but with aninspection window.

As mentioned above, the fitting housing 2240 may be configured toremovably detach from to the front cap 2220, while in other examples,the fitting housing may be integrally formed with the front cap 2220 orotherwise configured not to be detached once joined. A piston assemblymay be movably located within the suction chamber 2210. The pistonassembly 2260 may be coupled to a spring assembly secured to the rearcap 2230 of the suction apparatus 2200. In other embodiments, the springassembly 2270 may also be secured about the proximal opening 2216 of thesuction chamber 2210. An opening 2232 may be provided in the rear cap2230 to permit insertion of a priming tool 2290 which is configured toprime the suction apparatus 2200. Once the suction apparatus 2200 isprimed and activated, the priming tool 2290 may be removed, and theopening 2232 on the rear cap 2230 may be closed by a rear cap seal 2280.The rear cap seal 2280 may be any type of seal that may prevent entry ofundesired contaminants or other environmental agents (e.g. water duringshowering) into the suction chamber 2210. In other examples, the rearcap seal may be attached to the rear cap by a tether. In still otherexamples, the rear cap seal may be configured with a passageway or slitand comprises a deformable material that permits insertion and/orremoval of the priming tool and reseals upon removal of the primingtool. In the latter embodiments, the rear cap seal need not be removedbefore priming or inserted back into the opening after removal of thepriming tool.

FIG. 24A is a perspective view of the embodiment of the suctionapparatus 2200 in a configuration before priming and comprising acollection chamber 2210 made of a translucent or optically clearmaterial, with the piston assembly 2260 in a proximal position and thepriming tool 2290 inserted into the opening 2232 of the rear cap 2230but not yet displacing the piston assembly 2260. To prime the suctionapparatus 2200, the priming tool 2290 may by further inserted throughthe opening 2232 of the rear cap 2230 to push the piston assembly 2260into the suction chamber 2210. Depending upon the particularconfiguration, the priming tool may be pushed until the piston assemblycontacts the distal end wall until it is adjacent the distal end wall ofthe suction chamber, until the springs are maximally extended, and/ormechanical interference between the priming tool and the rear cap resistfurther insertion. FIG. 24B depicts the suction apparatus 2200 in theprimed configuration. The priming tool 2290 has pushed the pistonassembly 2260 into a distal position and has extended the springs 2300coupling the piston assembly 2260 to the spring assembly 2270 andgenerated potential energy within the springs 2300. Upon removal of thepriming tool 2290, the springs 2300 are able to exert a proximaldirected force onto the piston assembly 2260, which is capable ofgenerating reduced pressure in the suction chamber 2210 and transmittingthe reduced pressure to a sealed wound enclosure coupled to the device2200. FIGS. 24C and 24D are superior and side elevational views of thedevice from FIG. 24A in an activated state and with the springs 2300having partially expended the potential energy from the fully primedconfiguration. As can be seen when the piston assembly 2260 is in apartially expended position, the suction chamber 2210 may be subdividedby the piston assembly 2260 into a collection chamber 2262 and a workingchamber 2264, where the collection chamber 2262 is the space between thepiston assembly 2260 and the distal end wall 2213 of the suction chamber2210, and the working chamber 2264 is the space between the proximal end2214 of the suction chamber 2210 and the piston assembly 2260 whichcontain the springs 2300. When the suction apparatus is in the primedconfiguration, the volume of the collection chamber may be about zero,or sometimes less than about 5 cc. In some instances, upon activation ofthe primed device, the collection chamber may increase in volume up toabout 3%, sometimes about 5% and other times about 10% or even about 20%until the force exerted by the springs 2300 is counterbalanced by theforce generated by the reduced pressure in the collection chamber 2310.

FIG. 25A provides a detailed superior view of the suction chamber 2210and FIG. 25B provides a cross-sectional view of the distal portion ofthe suction chamber 2210 from FIG. 25A. As may be seen in theperspective views in FIGS. 22 to 24B, the suction chamber 2210, maycomprise a non-circular cross-sectional shape with respect to atransverse plane to the movement axis of the piston assembly, which insome configurations lies between the distal end 2212 and proximal end2214 of the suction chamber 2210. In other examples, the cross-sectionalshape of the suction chamber may have any of a variety of other types ofgeometric configurations (e.g., cylindrical, rectangular, etc.). Asmentioned previously, the distal end wall 2213 of the suction chamber2210 may further comprise a distal opening to permit communication withthe suction chamber. The distal end wall 2213 of the suction chamber2210 may further comprise a conduit 2330 or other extension structure.The conduit 2330 comprises a conduit lumen 2340 with a conduit opening2342 which are in fluid communication with the collection chamber 2310of the suction chamber via the distal opening 2215 of the distal endwall 2213. The conduit 2330 may comprise any of a variety of notches2350, grooves or flanges, which may facilitate attachment of the conduit2330 to one or more components associated with the fitting housing 2240.

Although a user-controlled valve may be provided in some embodiments toopen or close fluid communication with the suction chamber, in someexamples, the fluid communication may be controlled automatically by thecoupling and/or decoupling of the device components. For example, theconduit 2330 of the device 2200 may also comprise an inner conduit 2380located in the main conduit lumen 2340, the inner conduit 2380comprising an inner conduit lumen 2382 and an inner conduit opening2384. Referring to FIG. 25B, a chamber slit seal 2390 may be locatedabout the inner conduit opening 2384. In its base configuration, thechamber slit seal 2390 may be configured with a normally closedconfiguration to block fluid communication through the conduit 2330. Insome examples, a chamber slit seal 2390 may be opened by inserting astructure through the seal to deform it and maintain the patency of theopening formed in the seal. As will be explained in greater detailbelow, in other examples, such as the slit seal 2390 in FIG. 25B, theslit seal 2390 may be configured to be pushed over, around, and/or downtoward the base of the inner conduit 2380 when a complementary structureis inserted into the main conduit lumen 2340.

FIG. 26A is a top component view of a fitting assembly 2600, comprisingthe fitting housing 2240, a fitting 2242 and a fitting slit seal 2602.As mentioned previously, the fitting housing 2240 may be configured topermanently or detachably couple to the front cap 2220 of the device2200, or may be integrally formed with the front cap. In the embodimentshown in FIG. 26A, fitting 2610 comprises a connector section 2604 thatis accessible through an opening 2606 in the fitting housing 2240 andpermits a complementary fit with the connector of another component. Forexample, connector section 2604 may be coupled to a connector of anextension tube or the attachment port of a sealing layer with a snap fitor an interference fit. In the specific example in FIG. 26A, theconnector section 2604 comprises multiple flanges 2608 which may be usedto provide a resistance fit with tubing, but may also be used with acomplementary connector to form a complementary interfit.

Referring to FIGS. 26A and 26B, the fitting 2242 may also comprise achamber connector 2610 with a fitting slit seal 2602. When the device isassembles, the chamber connector 2610 may be located within the frontcap 2220 of the device 2200, but the particular location may vary withthe particular embodiment. The fitting slit seal 2602 may comprise adistal ring 2612 with an inner profile configured to engage a groove2614 on the chamber connector 2610 of the fitting 2242. The outerprofile of the seal 2602 and/or the distal ring 2612 may be configuredto seal against the inner surface main conduit lumen 2340. The fittingslit seal 2602 may also comprise a slit that provides a deformablepassageway through the seal 2602. Thus, in some embodiments, the fittingslit seal 2602 may be configured to both form an airtight seal betweenthe chamber connector 2610 and the conduit lumen 2340 of the suctionchamber 2210 and also to control fluid communication through the fittingassembly 2600. FIG. 26B illustrates a side cross sectional view offitting 2610 coupled to the fitting slit seal 2612 at the fitting'sproximal end.

Referring back to FIG. 26A, fitting assembly 2600 may also comprise aninterlocking structure that comprises at least one resilient tab 2616that is disposed on and project outwardly from a base member 2618coupled or integrally formed with the fitting 2242. When the fittingassembly 2600 is coupled to the suction chamber 2210, the tabs 2616 areconfigured to engage complementary recesses (2350 in FIGS. 25A and 25B)on the conduit 2330 of the suction chamber 2210. An interlockingmechanism may resist or prevents inadvertent decoupling of the fitting2242 from the suction chamber 2210. The fitting housing 2240 may furthercomprise one or more release structures or buttons 2622 that are coupledto or interface with the levers 2624 of the projecting tabs 2618.Depressing the buttons 2622 will release the interlocking mechanism bydisplacing the tabs 2616 from the notches 2350 on the suction chamber2210 and permit decoupling of the fitting 2242 and fitting housing 2240from the front cap 2220 and the suction chamber conduit 2330. Therelease buttons 2622 may comprise one or more textured gripping surfaces2626 that may facilitate manual connection or disconnection of thefitting 2242.

FIG. 27A is a schematic superior cut-away view of the suction chamber2210 and the fitting 2242 of the fitting assembly 2600 when the fitting2242 is fully inserted into the conduit 2330. As illustrated, the tabs2616 projecting from the base member 2618 of the fitting 2242 form aninterfit with the notches 2350 on the surface of the suction chamberconduit 2330. FIGS. 27B and 27C are side cross sectional views of aportion of the suction chamber 2210 and the fitting 2242, before andafter the fitting 2242 has been fully seated into the conduit 2330.FIGS. 27B and 27C further illustrate the connecting mechanism betweenchamber slit seal 2390 on the inner conduit 2380 and fitting slit seal2602 of the fitting 2242. In FIG. 27B, when fitting 2242 is insertedinto the conduit 2330, the fitting slit seal 2602 initially contactschamber slit seal 2390, which is mounted on a seal base 2392. Asillustrated in FIG. 27C, further insertion causes the edge 2628 of thechamber connector 2610 to exert a force along the perimeter 2660 of thechamber slit seal 2390. An inner gap 2632 and/or an outer gap 2634 aboutthe chamber slit seal 2390 provide space for the chamber slit seal 2390to deform or compress away from the edge 2628 of the chamber connector2610. This results in the enlargement of the opening or slit 2636 of thechamber slit seal 2390 as it is pushed proximally away from the innerconduit opening 2384. In some examples, the inner and outer gaps 26322634 may also reduce the frictional resistance of the chamber slit seal2390 against the inner conduit 2380 or the surface of the conduit lumen2340, respectively. As the fitting 2242 is further inserted into theconduit lumen 2340, the exposed inner conduit 2380 penetrates throughthe slit 2603 of the fitting slit seal 2602, thereby opening fluidcommunication from the suction chamber 2210, through the distal opening2215 of the suction chamber 2210, through the inner conduit 2380 andthrough the fitting 2242. In the embodiment depicted in FIGS. 27A to27C, the tabs 2616 and the notches 2350 of the locking mechanism may beused to provide rotational alignment of the between the fitting slitseal 2602 and the chamber slit seal 2390, if needed. This may be usefulwhere the slits of the seals 2602 and 2390 are single linear slits. Inother configurations where the slits are multiple radial slits,rotational alignment may or may not affect the patency of the fluidcommunication.

When fitting 2242 is decoupled from the suction chamber conduit 2330, ofthe withdrawal of the inner conduit 2380 from the fitting slit seal 2602results in closure of the fluid passageways to the sealed wound and maylimit air entry into the wound during decoupling. As the fitting 2242 isfurther separated, the edge 2628 of the chamber connector 2610 iswithdrawn and the chamber slit seal 2380 is able to elastically revertback to a closed position to seal the suction chamber 2210. In someembodiments, chamber slit seal 2380 is able to elastically revert backto a closed position with the aid of a coaxially mounted coil spring.Although both seals 2602 and 2390 are closed, the outer surface of thefitting slit seal 2602 continues to form a seal with the conduit lumen2340 until further separation occurs. As may be seen in FIGS. 2527B and27C, the conduit lumen 2340 of suction chamber 2210 has a non-uniformdiameter along it longitudinal length, and may comprise a proximalsegment 2638 having a reduced diameter relative to the distal segment2640. The transition in diameter between the proximal and distalsegments 2638 and 2640 may be gradual or stepped. The conduit lumen2340, for example, comprises at least one step transition region 2642between the segments 2638 and 2640. In some examples, step transitionregion may provide different tactile feedback compared to gradualtransitions.

The slit seal may be fluid impervious and may be fabricated from any ofsuitable resilient materials, such as, but not limited to, syntheticelastomer, silicone rubber, or natural rubber. The seal material may becompatible with wound exudates that may be collected by the suctionchamber during a reduced pressure treatment. The seal material may besterilized by treatment of radiation, steam, ethylene oxide or othersuitable techniques known to those skilled in the art.

Turning to FIGS. 28A and 28B now, the spring assembly 2270, which ismounted at the proximal end of the suction chamber and covered by thechamber rear cap, comprises a spring carrier 2820 and a U-shaped springretainer 2810 containing two bushings 2830 mounted on the two verticalrails 2812 of the spring retainer 2810. Two substantially constant forcesprings (not shown in this figure) may each comprise a coiled bodycoupled to and wrapped around bushing 2830 and a free end distallyextended and attached to the piston assembly. The springs may or may notbe constant force springs. The spring attachment mechanism will bediscussed in greater detail below. The spring carrier 2820 comprises acentral opening 2824 and two side openings 2826. The central opening2824 is configured to permit passage of the priming tool to access anddisplace the piston assembly. The side openings 2826 are configured tohouse the bushings 2830 and the springs when the spring retainer 2810 iscoupled to the spring carrier 2820. As shown in this figure, multipleridges 2821 may be located adjacent the side openings 2826 to limit themovement of the bushings 2830 and springs coiled around bushings 2830,thereby reducing deflections or deformations of the springs duringoperation of the suction apparatus. The spring carrier 2820 may alsocomprise resilient tabs 2822 that may slidably engage one or moregrooves on the priming tool shaft, which may reduce angular deviationsof the priming tool with respect to the longitudinal movement axis ofthe seal. The spring carrier 2820 may also comprises two interlockingstructures 2823 configured to releasably lock the priming tool in placeafter the suction apparatus is primed. The interlocking mechanism willbe described in detail later. Fixation structures 2828 may be providedto form a snapfit or other type of interfit with complementarystructures on the suction chamber.

FIGS. 29A and 29B are component views of the piston assembly 2260 thatcomprises a piston seal 2910 and a piston 2920. The piston assembly 2260may be configured to traverse between the distal end and the proximalend of the suction chamber while maintaining a substantially airtightseal. As mentioned previously, the piston assembly 2260 provides anairtight separation the suction chamber between a collection chamber anda working chamber. In the depicted embodiment, the piston seal 2910 hasa non-circular, elliptical cross-sectional shape with respect to itsmovement axis in the suction chamber, but in other embodiments, othershapes as described herein may be used. The piston seal 2910 maycomprise a side wall 2911 and a distal end wall 2912. The side wall 2911of the piston seal 2910 further comprises a distal perimeter ridge 2914and a proximal perimeter ridge 2916, the dimensions of which may belarger than that of the side wall 2911 of piston seal 2910. The ridges2914 and 2916 may be configured to be in a sliding contact with theinterior surface of the suction chamber. They may provide a sealedcontact while limiting sliding friction. The exterior surfaces of thepiston seal and/or the interior surfaces of the suction chamber maycomprise a friction-reducing lubricant or a lubricious coating material.

The piston seal 2910 may be detachably coupled to the piston 2920 or insome embodiments, the piston seal 2910 and the piston 2910 may beintegrally formed. In the depicted embodiment, the piston 2920 maycomprise an elliptical frame with a side wall 2924. The distal portionof side wall 2920 may comprise a recess 2926 and a raised edge or flange2928 configured form a complementary interfit with the piston seal 2910.The proximal perimeter edge 2930 of side wall 2922 may have acomplementary shape to the distal edge 2829 of the spring carrier 2820.In the depicted embodiment, both the proximal edge 2930 of the pistonside wall 2922 and the distal perimeter edge 2829 of the spring carrierhave a curved, non-planar configuration. As mentioned previously, theseal and/or seal mount (e.g. piston 2920) may have a variablelongitudinal length along its perimeter. In some instances, an increasedlongitudinal dimension may provide additional stability to the sealalong a dimension of the seal. In some examples, the side length along asection of the perimeter of the piston 2920 may be related to thetransverse dimension intersecting a) that side length of the perimeterand b) the central movement axis of the seal and/or piston. In theexample in FIG. 29A, the lateral longitudinal surface of the piston 2920may have a longitudinal length 2932, based upon the increased width 2934of the piston 2920 relative to the height 2936 of the suction chamber2210 (corresponding to the increased width and reduced height of thesuction chamber 2210). In comparison, the superior longitudinal surfaceof the piston 2920 may have a longitudinal length 2938 that is smallerthan the longitudinal length 2932 of the lateral longitudinal surfacefrom the reduced height 2936 of the piston 2920.

Referring to FIGS. 29A, 29B and 30, the piston 2920 may also comprise acentral opening 2940 which may be aligned with the central opening 2824of spring carrier 2820. The piston central opening 2940 may beconfigured to provide passage of the distal ends of the constant forcesprings. FIG. 29C provides a frontal elevational view of the piston2920. The distal regions 2952 of the constant force springs 2950(depicted only in FIG. 30) may extend through the central opening 2940and are coupled to a pair of spring retaining structures 2930 disposedon the front surface of piston 2920. In this particular embodiment, theretaining structures 2930 are configured to be inserted into aperturesprovided on the springs and may or may not maintain their coupling usingresidual spring force that may be present in the springs in theretracted configuration. The retaining structure and the springs mayhave any of a variety of other coupling configurations, however (e.g.the retaining structures may comprise posts which block displacement ofT-shaped spring ends). Between the central opening 2940 and theretaining structures 2942 are curved support surfaces 2944 which areconfigured to push against the springs. In some examples, the length ofthe curved support surfaces 2944 between the central opening 2940 andthe retaining structures 2930 may be at least one or one and a halftimes the width of the springs, while in other examples may be two orthree times or four times the width of the springs. In some examples,the curved support surfaces 2944 provide a substantial surface area todistribute the pushing forces and may reduce the risk of damage to thesprings. Referring back to FIG. 29A, the piston 2920 may furthercomprise convex supports 2946 adjacent to the central opening 2940,which may also support the springs as the springs converge into thecentral opening 2940. The convex supports 2946 may have a curved lengthof at least about the width of the springs, but in other examples may beat least two or three times the width of the springs. Referring to FIGS.29A and 30, the convex supports 2926 may also comprise a concave region2948, which may accommodate the coils of the spring and the springcarriers 2830 when the piston assembly 2260 is in a retractedconfiguration. Although the piston assembly 2260 and the spring assembly2270 depicted in FIGS. 28A to 29B utilized two springs, in otherexamples, one spring, three springs, four springs, or five or moresprings may be used. The number of springs, the type of springs, and thewidth and length of the springs may be varied, and in other examples,non-spring bias members may be used (e.g. sealed pneumatic shocks).

FIGS. 31A to 31C schematically illustrate one example of a primingprocedure of the suction apparatus 2200 with a priming tool 2290 fromFIGS. 23A and 23B, where the springs have not been shown to betterillustrate the interactions between the piston assembly 2260, springassembly 2270 and the priming tool 2290. The priming tool 2290 comprisesa tool shaft 3100 with a distal recess 3110 and a proximal recess 3120on each side of the shaft 3100. Located between the recesses 3110 and3120 is a non-recessed portion of the shaft 3100. The distal end 3130 ofthe priming tool 2290 is has a cross sectional shape and size that isable to pass through the central opening 2824 of the spring assembly2270 to contact the piston 2920 of the piston assembly 2260. During thepriming procedure, the priming tool 2290 may be pushed against thepiston 2920 but is not configured to couple or attach to the piston2920. In other embodiments, however, the distal end 3130 of the primingtool 2290 and the piston 2920 may be configured to form a complementaryinterlocking fit or interference fit. Before priming, the springs willpull and maintain the piston assembly 2260 into a proximal or retractedposition against the spring assembly 2270. As the priming tool 2290 isinserted into the suction apparatus, the resilient tabs 2822 on thespring assembly 2270 will slidably engage the distal recess 3110 on thetool shaft 3100. As the priming tool 2290 is further inserted, the usermay receive tactile feedback of increased resistance as the tabs 2822are resiliently displaced out of the distal recesses 3110. Furtherinsertion may provide additional tactile feedback from increasedfrictional resistance by the tabs 2822 against the non-recessed portion3112 of the shaft 3100. As the priming tool 2290 is further inserted,the piston assembly 2260 is separated from the spring assembly 2270 andthe constant force springs or bias members attaching the assemblies 2260and 2270 will elongate and generate potential energy. As piston assembly2260 is further displaced distally, the tabs 2822 will then engage theproximal recess 3120 on the prime tool shaft 3100. The position andlength of the of the non-recessed portion 3112 and the recesses 3110 and3120 of the shaft 3100 may be configured to provide the user withtactile feedback indication, or may be provided to resist ejection ofthe priming tool 2290 out of the suction apparatus. For example, if thewound or fluid communication to the wound is incompletely sealed, or ifthere is an excessive volume of air or exudates the wound, uponactivation of the suction apparatus, the piston assembly 2260 mayretract suddenly. The non-recessed portion 3112 of the priming tool 2290may provide at least partial retention of the tool 2290 so that the usercan reprime the suction apparatus. The recesses 3110 and 3120 may beconfigured with ramped proximal and distal surfaces movement of the tabs2822 in and out of the recesses 3110 and 3120.

Upon full priming of the suction apparatus, latches 3140 located on theprime tool shaft 3110 may engage the interlocking structures 2823 on thespring assembly 2270 to locks the priming tool 2290 into place, asdepicted in FIG. 31C. The priming tool 2290 may be left in the lockedconfiguration in the suction apparatus, and may even be stored and/ordistributed in a primed poison. The locking mechanism also permits thesuction apparatus to be primed without requiring that the suctionapparatus be already coupled to the sealant layer. Thus, the user neednot be concerned about uncoupling the suction apparatus or unsealing thesealant layer during the priming procedure, and may handle or orient thesuction apparatus in any manner, e.g. abutting the connector surface ofthe suction apparatus against a table or wall to provide leverage whenpushing the priming tool.

To activate the primed suction apparatus, the user may depress therelease buttons 3150 located at the proximal end of the prime tool 2290.Pressing the release buttons 3150 disengage the latches disengageslatches 3140 from the interlocking structures 2823, thereby permittingthe removal of the priming tool 2290 out of the suction chamber. Therelease buttons 3150 may also comprise one or more textured grippingstructures or materials to facilitate latch release. Although theembodiment depicts in FIGS. 31A to 31C comprises a priming tool 2290with two latches 3140 and two release buttons 3150, in otherembodiments, a different number latches and/or buttons may be provided,or a different configuration of a locking mechanism may be provided(e.g. a locking pin that may be inserted and removed by the user).

As described previously, once the priming tool 2290 is proximallywithdrawn, the piston assembly will be retracted by the charged constantforce springs. Such movement will expand the combined volume of thespace below the piston assembly and the sealed wound enclosure, andreduce the pressure level therein. Where there has been an inadvertentleak in the system or excessive air or exudates in the wound, thepriming tool 2290 may be used to reprime the device. In theseembodiments, the method for using the suction apparatus may furthercomprise resealing the wound and/or reseating one or more connectors ofthe reduced pressure therapy device, and repositioning the slidable sealor piston assembly to the extended or primed position and reactivatingthe device.

In some embodiments, the method of treating an area of damaged tissuemay comprise affixing a sealant layer around an area of tissue to betreated; creating a sealed enclosure around the area of the tissue withthe sealant layer, inserting a collection chamber into a housing chamberand priming the collection chamber; creating a fluid communicationbetween the collection chamber and the sealed wound enclosure;activating the collection chamber to create a reduced pressure levelwithin the sealed wound enclosure; if the collection chamber is filledup with wound exudates, terminating the fluid communication between thecollection chamber and the wound seal and releasing the collectionchamber from the wound site; withdrawing the collection chamber from thehousing chamber and replacing it with a new collection chamber; andrepeating the steps as appropriate to continue a reduced pressuretreatment.

Although the embodiments herein have been described in relation tocertain examples, various additional embodiments and alterations to thedescribed examples are contemplated within the scope of the invention.Thus, no part of the foregoing description should be interpreted tolimit the scope of the invention as set forth in the following claims.For all of the embodiments described above, the steps of the methodsneed not be performed sequentially. Accordingly, it is not intended thatthe invention be limited, except as by the appended claims.

1. A system for treatment of a patient, comprising: a. a sealable woundcovering comprising a sealant layer and a flexible attachment portconfigured with a lumen that passes through the sealant layer; b. areduced pressure generating assembly, comprising: i. a removable suctionchamber with a longitudinal axis and a non-circular cross-sectionalshape transverse to the longitudinal axis and a volume of 150 cc orless; ii. a piston assembly configured to slide in the suction chamberalong the longitudinal axis and having a non-circular cross-sectionalshape transverse to the longitudinal axis and a non-planar proximalperimeter; iii. at least two substantially constant force spring coilscoupled to the piston assembly and configured to reduce pressure in thesuction chamber by at least 50 mmHg; iv. a priming tool configured topush the piston assembly and comprising a locking mechanism and v. aconnector tube configured to releasably attach to the sealable woundcovering and to releasably attach to the removable suction chamber.